搜题
共用题干
Black Holes
Most scientists agree that black holes exist but are nearly impossible to locate.A black
hole in the universe is not a solid object,like a planet,but it is shaped like a sphere（球体）.
Astronomers（天文学家）think that at the center of a black hole there is a single point in
space with infinite（无限的）density（稠密）.This single point is called a singularity（奇点）.
If the singularity theory is correct,it means that when a massive star collapses,all the
material in it disappears into the singularity.The center of a black hole would not really be a
hole at all,but an infinitely dense point.Anything that crosses the black hole is pulled in by
its great gravity.
Although black holes do exist,they are difficult to observe.These are the reasons.
No light or anything else comes out of black holes.As a result,they are invisible to
a telescope.
In astronomical terms,black holes are truly tiny.For example,a black hole formed
by the collapse of a giant star would have an event horizon（视界）only 18 miles across.
The nearest black holes would be dozens of light years away from Earth.One light
year is about 6 trillion（万亿）miles. Even the most powerlul telescopes could not pick out
an object so small at such a great distance.
In 1994 the Hubble Space Telescope provided evidence that black holes exist.There
are still answers to be found,however,so black holes remain one of the mysteries of the
universe.
The Hubble Space Telescope helps scientists to understand the nature of the universe.
A:Right
B:Wrong
C:Not mentioned
Black Holes
Most scientists agree that black holes exist but are nearly impossible to locate.A black
hole in the universe is not a solid object,like a planet,but it is shaped like a sphere（球体）.
Astronomers（天文学家）think that at the center of a black hole there is a single point in
space with infinite（无限的）density（稠密）.This single point is called a singularity（奇点）.
If the singularity theory is correct,it means that when a massive star collapses,all the
material in it disappears into the singularity.The center of a black hole would not really be a
hole at all,but an infinitely dense point.Anything that crosses the black hole is pulled in by
its great gravity.
Although black holes do exist,they are difficult to observe.These are the reasons.
No light or anything else comes out of black holes.As a result,they are invisible to
a telescope.
In astronomical terms,black holes are truly tiny.For example,a black hole formed
by the collapse of a giant star would have an event horizon（视界）only 18 miles across.
The nearest black holes would be dozens of light years away from Earth.One light
year is about 6 trillion（万亿）miles. Even the most powerlul telescopes could not pick out
an object so small at such a great distance.
In 1994 the Hubble Space Telescope provided evidence that black holes exist.There
are still answers to be found,however,so black holes remain one of the mysteries of the
universe.
The Hubble Space Telescope helps scientists to understand the nature of the universe.
A:Right
B:Wrong
C:Not mentioned
共用题干
Dangers Await Babies With Altitude
Women who live in the world's highest communities tend to give birth to underweight babies,a new
study suggests.These babies may grow into adults with a high risk of heart disease and strokes.
Research has hinted that newborns in mountain communities are lighter than average.But it wasn't
clear whether this is due to reduced oxygen levels at high altitude or because their mothers are
under-nourished一many people who live at high altitudes are relatively poor compared with those living lower
down.
To find out more,Dino Giussani and his team at Cambridge University studied the records of 400 births
in Bolivia during 1997 and 1998.The babies were born in both rich and poor areas of two cities:La Paz and
Santa Cruz.La Paz is the highest city in the world,at 3.65 kilometers above sea level,while Santa Cruz is
much lower,at 0.44 kilometers.
Sure enough,Giussani found that the average birthweight of babies in La Paz was significantly lower than
in Santa Cruz.This was true in both high and low-income families.Even babies born to poor families in
Santa Cruz were heavier on average than babies born to wealthy families in lofty La Paz."We were very
surprised by this result,"says Giussani.
The results suggest that babies born at high altitude are deprived of oxygen before birth."This may
trigger the release or suppression of hormones that regulate growth of the unborn child," says Giussani.
His team also found that high-altitude babies tended to have relatively larger heads compared with their
bodies.This is probably because a fetus starved of oxygen will send oxygenated blood to the brain in
preference to the rest of the body.
Giussani wants to find out if such babies have a higher risk of disease in later life. People born in La
Paz might be prone to heart trouble in adulthood,for example.Low birth weight is a risk factor for coronary
heart disease.And newborns with a high ratio of head size to body weight are often predisposed to high blood
pressure and strokes in later life.
The weight of a newborn has something to do with the supply of oxygen even when he is still in his mother'swomb.
A:Right
B:Wrong
C:Not mentioned
Dangers Await Babies With Altitude
Women who live in the world's highest communities tend to give birth to underweight babies,a new
study suggests.These babies may grow into adults with a high risk of heart disease and strokes.
Research has hinted that newborns in mountain communities are lighter than average.But it wasn't
clear whether this is due to reduced oxygen levels at high altitude or because their mothers are
under-nourished一many people who live at high altitudes are relatively poor compared with those living lower
down.
To find out more,Dino Giussani and his team at Cambridge University studied the records of 400 births
in Bolivia during 1997 and 1998.The babies were born in both rich and poor areas of two cities:La Paz and
Santa Cruz.La Paz is the highest city in the world,at 3.65 kilometers above sea level,while Santa Cruz is
much lower,at 0.44 kilometers.
Sure enough,Giussani found that the average birthweight of babies in La Paz was significantly lower than
in Santa Cruz.This was true in both high and low-income families.Even babies born to poor families in
Santa Cruz were heavier on average than babies born to wealthy families in lofty La Paz."We were very
surprised by this result,"says Giussani.
The results suggest that babies born at high altitude are deprived of oxygen before birth."This may
trigger the release or suppression of hormones that regulate growth of the unborn child," says Giussani.
His team also found that high-altitude babies tended to have relatively larger heads compared with their
bodies.This is probably because a fetus starved of oxygen will send oxygenated blood to the brain in
preference to the rest of the body.
Giussani wants to find out if such babies have a higher risk of disease in later life. People born in La
Paz might be prone to heart trouble in adulthood,for example.Low birth weight is a risk factor for coronary
heart disease.And newborns with a high ratio of head size to body weight are often predisposed to high blood
pressure and strokes in later life.
The weight of a newborn has something to do with the supply of oxygen even when he is still in his mother'swomb.
A:Right
B:Wrong
C:Not mentioned
They didn't seem to appreciate the magnitude of the problem.
A:existence
B:importance
C:cause
D:situation
A:existence
B:importance
C:cause
D:situation
共用题干
Travel Across Africa
For six hours we shot through the barren（荒芜的）landscape of the Karoo desert in
South Africa. Just rocks and sand and baking sun. Knowing our journey was ending,Daniel and I just wanted to remember all we had seen and done. He used a camera. I used words. I had already finished three notebooks and was into the fourth,a beautiful leather notebook I'd bought in a market in Mozambique.
Southern Africa was full of stories and visions.We were almost drunk on sensations,the roaring（咆哮）of the water at Victoria Falls, the impossible silence of the Okavango Delta in Botswana.
And then the other things:dogs in the streets,whole families in Soweto living in one room,a kilometre from clean water.
As we drove towards the setting sun,a quietness fell over us. The road was empty一we hadn't seen another car for hours.And as I drove,something caught my eye,something moving close enough to touch them,to smell their hot breath. I didn't know how long they had been there next to us.
I shouted to Dan:“Look!”But he was in a deep sleep,his camera lying useless by his feet. They raced the car for a few seconds,then disappeared far behind us,a memory of he- roic forms in the red landscape.
When Daniel woke up an hour later I told him what had happened.
”Wild horses?”he said.”Why didn't you wake me up,Sophia?”
”I tried. But they were gone after a few seconds.”
”Are you sure you didn't dream it?”
”You were the one who was sleeping!”
”Typical”,he said.”The best photos are the ones we never take.”
We checked into a dusty hotel and slept the sleep of the dead.
The horses didn't come near the car.
A: Right
B: Wrong
C: Not mentioned
Travel Across Africa
For six hours we shot through the barren（荒芜的）landscape of the Karoo desert in
South Africa. Just rocks and sand and baking sun. Knowing our journey was ending,Daniel and I just wanted to remember all we had seen and done. He used a camera. I used words. I had already finished three notebooks and was into the fourth,a beautiful leather notebook I'd bought in a market in Mozambique.
Southern Africa was full of stories and visions.We were almost drunk on sensations,the roaring（咆哮）of the water at Victoria Falls, the impossible silence of the Okavango Delta in Botswana.
And then the other things:dogs in the streets,whole families in Soweto living in one room,a kilometre from clean water.
As we drove towards the setting sun,a quietness fell over us. The road was empty一we hadn't seen another car for hours.And as I drove,something caught my eye,something moving close enough to touch them,to smell their hot breath. I didn't know how long they had been there next to us.
I shouted to Dan:“Look!”But he was in a deep sleep,his camera lying useless by his feet. They raced the car for a few seconds,then disappeared far behind us,a memory of he- roic forms in the red landscape.
When Daniel woke up an hour later I told him what had happened.
”Wild horses?”he said.”Why didn't you wake me up,Sophia?”
”I tried. But they were gone after a few seconds.”
”Are you sure you didn't dream it?”
”You were the one who was sleeping!”
”Typical”,he said.”The best photos are the ones we never take.”
We checked into a dusty hotel and slept the sleep of the dead.
The horses didn't come near the car.
A: Right
B: Wrong
C: Not mentioned
共用题干
The Greatest Mystery of Whales
The whale is a warm一blooded,air-breathing animal,giving birth to its young alive,sucking them一and,
like all mammals,originated on land. There are many________________(51)of this. Its front flippers（鳍状肢）,
used for steering and stability,are traces of feet.
Immense strength is________________(52)into the great body of the big whales,and in fact most of a
whale's body is one gigantic muscle.The blue whale's pulling strength has been estimated________________(53)
400 horsepower. One specimen was reported to have towed（拖）a whaling vessel for seven hours at the
_______________ (54)of eight knot（节）.
An angry whale will________________(55).A famous example of this was the fate of Whaler Essex,
________________(56)was sunk off the coast of South America early in the last century. More recently,steel ships
have ___________( 57 ) their plates buckled（使弯曲）in the same way. Sperm whales（抹香鲸）were known
to seize the old-time whaleboats in their jaws and crush them.
The greatest________________(58)of whales is their diving ability.The sperm whale dives to the bottom foi
his________________(59)food,the octopus（章鱼）.In that search he is known to go as far down as 3 , 200 feet,
where the________________(60)is 1,400 pounds,to a square inch.Doing so he will________________(61)underwa-
ter as long as one hour. Two special skills are involved in this storing up enough________________(62)(all
whales are air-breathed)and tolerating the great change in pressure.Just how he does it scientists have nol
_______________ (63).It is believed that some of the oxygen is stored in a special________________(64)of blood
vessels,rather than just held in the lungs.And it is believed that a special kind of oil in his head is some sort
of a compensating mechanism that________________(65)adjusts the internal pressure of his body.But since you
can't bring a live whale into the laboratory for study,no one knows just how these things work.
_________(54)
A:number
B:degree
C:distance
D:rate
The Greatest Mystery of Whales
The whale is a warm一blooded,air-breathing animal,giving birth to its young alive,sucking them一and,
like all mammals,originated on land. There are many________________(51)of this. Its front flippers（鳍状肢）,
used for steering and stability,are traces of feet.
Immense strength is________________(52)into the great body of the big whales,and in fact most of a
whale's body is one gigantic muscle.The blue whale's pulling strength has been estimated________________(53)
400 horsepower. One specimen was reported to have towed（拖）a whaling vessel for seven hours at the
_______________ (54)of eight knot（节）.
An angry whale will________________(55).A famous example of this was the fate of Whaler Essex,
________________(56)was sunk off the coast of South America early in the last century. More recently,steel ships
have ___________( 57 ) their plates buckled（使弯曲）in the same way. Sperm whales（抹香鲸）were known
to seize the old-time whaleboats in their jaws and crush them.
The greatest________________(58)of whales is their diving ability.The sperm whale dives to the bottom foi
his________________(59)food,the octopus（章鱼）.In that search he is known to go as far down as 3 , 200 feet,
where the________________(60)is 1,400 pounds,to a square inch.Doing so he will________________(61)underwa-
ter as long as one hour. Two special skills are involved in this storing up enough________________(62)(all
whales are air-breathed)and tolerating the great change in pressure.Just how he does it scientists have nol
_______________ (63).It is believed that some of the oxygen is stored in a special________________(64)of blood
vessels,rather than just held in the lungs.And it is believed that a special kind of oil in his head is some sort
of a compensating mechanism that________________(65)adjusts the internal pressure of his body.But since you
can't bring a live whale into the laboratory for study,no one knows just how these things work.
_________(54)
A:number
B:degree
C:distance
D:rate
共用题干
Most Adults in U.S.Have Low Risk of Heart Disease
More than 80 percent of U .S.adults have a less than 10-percent risk of developing heart dis- ease in the next 10 years,according to a report in the Journal of the American College of Cardiolo-gy（心脏病学）.Just 3 percent have a risk that exceeds 20 percent.
“I hope that these numbers will give physicians,researchers,health policy analysts,and others a better idea of how coronary（心脏冠状动脉的）heart disease is distributed in the U. S. population ,” lead（带头的）author Dr. Earl S. Ford , from the Centers for Disease Control and Prevention in Atlanta,said in a statement.
The findings are based on analysis of data from 13,769 subjects,between 20 and 79 years of age , who participated in the Third National Health and Nutrition（营养的供给）Examination Sur- vey from 1988 to 1994.
Overall,82 percent of adults had a risk of less than 10 percent,15 percent had a risk that fell between 10 to 20 percent and 3 percent had a risk above 20 percent,
The proportion of subjects in the highest risk group increased with advancing age,and men were more likely than women to be in this group. By contrast, race or ethnicity（种族划分）had little effect on risk distributions.
Although the report suggests that most adults have a low 10-year risk of heart disease,a large proportion have a high or immediate risk,Dr. Daniel S .Berman,from Cedars-Sinai Medi- cal Center in Los Angeles,and Dr. Nathan D.Wong,from the University of California at Irvine, note in a related editorial.
Aggressive treatment measures and public health strategies are needed to shift the overall population risk downward,they add.
According to the Journal of the American College of Cardiology,_______of the U.S. adults had a risk of developing heart disease above 20 percent in the next 10 years.
A: three percent
B:ten percent
C:twenty percent
D: eighty-two percent
Most Adults in U.S.Have Low Risk of Heart Disease
More than 80 percent of U .S.adults have a less than 10-percent risk of developing heart dis- ease in the next 10 years,according to a report in the Journal of the American College of Cardiolo-gy（心脏病学）.Just 3 percent have a risk that exceeds 20 percent.
“I hope that these numbers will give physicians,researchers,health policy analysts,and others a better idea of how coronary（心脏冠状动脉的）heart disease is distributed in the U. S. population ,” lead（带头的）author Dr. Earl S. Ford , from the Centers for Disease Control and Prevention in Atlanta,said in a statement.
The findings are based on analysis of data from 13,769 subjects,between 20 and 79 years of age , who participated in the Third National Health and Nutrition（营养的供给）Examination Sur- vey from 1988 to 1994.
Overall,82 percent of adults had a risk of less than 10 percent,15 percent had a risk that fell between 10 to 20 percent and 3 percent had a risk above 20 percent,
The proportion of subjects in the highest risk group increased with advancing age,and men were more likely than women to be in this group. By contrast, race or ethnicity（种族划分）had little effect on risk distributions.
Although the report suggests that most adults have a low 10-year risk of heart disease,a large proportion have a high or immediate risk,Dr. Daniel S .Berman,from Cedars-Sinai Medi- cal Center in Los Angeles,and Dr. Nathan D.Wong,from the University of California at Irvine, note in a related editorial.
Aggressive treatment measures and public health strategies are needed to shift the overall population risk downward,they add.
According to the Journal of the American College of Cardiology,_______of the U.S. adults had a risk of developing heart disease above 20 percent in the next 10 years.
A: three percent
B:ten percent
C:twenty percent
D: eighty-two percent
共用题干
Climate Change:The Long Reach
1.Earth is warming.Sea levels are rising.There's more carbon in the air,and Arctic ice is melting faster than at any time in recorded history.Scientists who study the environment to better gauge（评估） Earth's future climate now argue that these changes may not reverse for a very long time.
2.People burn fossil fuels like coal and oil for energy.That burning releases carbon dioxide,a colorless gas.In the air,this gas traps heat at Earth's surface.And the more carbon dioxide released,the more the planet warms.If current consumption of fossil fuels doesn't slow,the long-term climate impacts could last thousands of years-and be more severe than scientists had been expecting.Climatologist Richard
Zeebe of the University of Hawaii at Manoa offers this conclusion in a new paper.
3.Most climate-change studies look at what's going to happen in the next century or so.During that time, changes in the planet' s environment could nudge（推动）global warming even higher.For example, snow and ice reflect sunlight back into space.But as these melt,sunlight can now reach-and warm-the exposed ground.This extra heat raises the air temperature even more,causing even more snow to melt.This type of rapid exaggeration of impacts is called a"fast feedback".
4.Zeebe says it's important to look at fast feedbacks.However,he adds,they're limited.From a climate change perspective,"This century is the most important time for the next few generations,"he told Science News."But the world is not ending in 2100."For this new study,Zeebe now focuses on"slow feedbacks".While fast feedback events unfold over decades or centuries,slow feedbacks can take thousands of years.Melting of continental ice sheets and the migration of plant life-as they relocate to more comfortable areas-are two examples of slow feedbacks.
5.Zeebe gathered information from previously published studies investigating how such processes played out over thousands of years during past dramatic changes in climate.Then he came up with a forecast for the future that accounts for both slow and fast feedback processes.Climate forecasts that use only fast feedbacks predict a 4.5 degree Celsius(8.1 degree Fahrenheit)change by the year 3000.But slow feedbacks added another 1.5℃-for a 6℃ total increase,Zeebe reports.He also found that slow feedback events will cause global warming to persist for thousands of years after people run out of fossil fuels to burn.
Melting of snow and ice enables sunlight to reach______.
A:the exposed ground
B:a very long time
C:the extra heat
D:recorded history
E:previously published studies
F:rapid exaggeration of impacts
Climate Change:The Long Reach
1.Earth is warming.Sea levels are rising.There's more carbon in the air,and Arctic ice is melting faster than at any time in recorded history.Scientists who study the environment to better gauge（评估） Earth's future climate now argue that these changes may not reverse for a very long time.
2.People burn fossil fuels like coal and oil for energy.That burning releases carbon dioxide,a colorless gas.In the air,this gas traps heat at Earth's surface.And the more carbon dioxide released,the more the planet warms.If current consumption of fossil fuels doesn't slow,the long-term climate impacts could last thousands of years-and be more severe than scientists had been expecting.Climatologist Richard
Zeebe of the University of Hawaii at Manoa offers this conclusion in a new paper.
3.Most climate-change studies look at what's going to happen in the next century or so.During that time, changes in the planet' s environment could nudge（推动）global warming even higher.For example, snow and ice reflect sunlight back into space.But as these melt,sunlight can now reach-and warm-the exposed ground.This extra heat raises the air temperature even more,causing even more snow to melt.This type of rapid exaggeration of impacts is called a"fast feedback".
4.Zeebe says it's important to look at fast feedbacks.However,he adds,they're limited.From a climate change perspective,"This century is the most important time for the next few generations,"he told Science News."But the world is not ending in 2100."For this new study,Zeebe now focuses on"slow feedbacks".While fast feedback events unfold over decades or centuries,slow feedbacks can take thousands of years.Melting of continental ice sheets and the migration of plant life-as they relocate to more comfortable areas-are two examples of slow feedbacks.
5.Zeebe gathered information from previously published studies investigating how such processes played out over thousands of years during past dramatic changes in climate.Then he came up with a forecast for the future that accounts for both slow and fast feedback processes.Climate forecasts that use only fast feedbacks predict a 4.5 degree Celsius(8.1 degree Fahrenheit)change by the year 3000.But slow feedbacks added another 1.5℃-for a 6℃ total increase,Zeebe reports.He also found that slow feedback events will cause global warming to persist for thousands of years after people run out of fossil fuels to burn.
Melting of snow and ice enables sunlight to reach______.
A:the exposed ground
B:a very long time
C:the extra heat
D:recorded history
E:previously published studies
F:rapid exaggeration of impacts
共用题干
第二篇
Saving Money
Where you save your money often depends on what you are saving for. If you are
saving to buy a CD（光盘）or to go to a concert, then probably you would keep your
money somewhere in your room.
If you are saving for a big purchase like a mountain bike or a school trip,where would
you save your money?
One place to save money is the bank.Putting your money in a savings account will
help your money earn more money. If you put your money in a piggy bank（猪形储蓄罐）,
one year later you'll still have the same amount of money you put in.If you put your money
in a savings account,one year later,you'll have more money than you put in.Why?
When you keep your money in a bank,your money earns interest.Interest is an
amount of money a bank pays you to use your money.The bank uses your money(and
the money of other people,too)to loan money to people and businesses.
The bank will send you a statement several times a year. A bank statement tells you
how much money you have in your account.It also tells you how much interest you have
earned.If you leave your money in the bank,you can watch it grow!
Another way you can save money is to buy a certificate of deposit or CD.If you have
some money that you don't need to use for a long time,this is a good way to make your
money grow.
You can buy a CD at a bank.You agree not to use the money for a certain period of
time.That period might be from six months to five years.You can't touch your money
during that time.If you do,you must pay a penalty,or fee.
A bank pays you interest for
A:wasting your money.
B:losing your money.
C:using your money.
D:decreasing your money.
第二篇
Saving Money
Where you save your money often depends on what you are saving for. If you are
saving to buy a CD（光盘）or to go to a concert, then probably you would keep your
money somewhere in your room.
If you are saving for a big purchase like a mountain bike or a school trip,where would
you save your money?
One place to save money is the bank.Putting your money in a savings account will
help your money earn more money. If you put your money in a piggy bank（猪形储蓄罐）,
one year later you'll still have the same amount of money you put in.If you put your money
in a savings account,one year later,you'll have more money than you put in.Why?
When you keep your money in a bank,your money earns interest.Interest is an
amount of money a bank pays you to use your money.The bank uses your money(and
the money of other people,too)to loan money to people and businesses.
The bank will send you a statement several times a year. A bank statement tells you
how much money you have in your account.It also tells you how much interest you have
earned.If you leave your money in the bank,you can watch it grow!
Another way you can save money is to buy a certificate of deposit or CD.If you have
some money that you don't need to use for a long time,this is a good way to make your
money grow.
You can buy a CD at a bank.You agree not to use the money for a certain period of
time.That period might be from six months to five years.You can't touch your money
during that time.If you do,you must pay a penalty,or fee.
A bank pays you interest for
A:wasting your money.
B:losing your money.
C:using your money.
D:decreasing your money.
共用题干
Organ Donation and Transplantation
1 Organ donation（捐献）and transplantation（移植）refers to the process by which organs or tissues
from one person are put into another person's body.
2 The number of people needing a transplant continues to rise faster than the number of donors.About
3,700 transplant candidates are added to the national waiting list each month.Each day,about 77 people
receive organ transplants.However,18 people die each day waiting for transplants that can't take place
because of the shortage of donated organs.
3 There are rio age limits on who can donate.Newborns as well as senior citizens have been organ
donors. If you are under age 18 , you must have a parent's or guardian's consent（同意）.If you are 18 years or
older,you can show you want to be an organ and tissue donor by signing a donor card.
4 Many people think that if they agree to donate their organs,the doctor or the emergency room staff
won't work as hard to save their life.This is not true.The transplant team is completely separate from the
medical staff working to save your life.The transplant team does not become involved with you until doctors
have determined that all possible efforts to save your life have failed.
5 If you need an organ transplant,your doctor will help you get on the national waiting list.Your name
will be added to a pool of names.When an organ donor becomes available,all the patients in the pool are
compared to that donor. Factors such as blood and tissue type, size of the organ, medical urgency（紧急）of
the patient's illness , time already spent on the waiting list, and distance between donor and recipient（接受
者）are considered.
Various factors are considered when deciding on_________.
A:donated organs
B:the national waiting list
C:a donor card
D:senior citizens
E:all possible efforts
F:the most suitable candidate
Organ Donation and Transplantation
1 Organ donation（捐献）and transplantation（移植）refers to the process by which organs or tissues
from one person are put into another person's body.
2 The number of people needing a transplant continues to rise faster than the number of donors.About
3,700 transplant candidates are added to the national waiting list each month.Each day,about 77 people
receive organ transplants.However,18 people die each day waiting for transplants that can't take place
because of the shortage of donated organs.
3 There are rio age limits on who can donate.Newborns as well as senior citizens have been organ
donors. If you are under age 18 , you must have a parent's or guardian's consent（同意）.If you are 18 years or
older,you can show you want to be an organ and tissue donor by signing a donor card.
4 Many people think that if they agree to donate their organs,the doctor or the emergency room staff
won't work as hard to save their life.This is not true.The transplant team is completely separate from the
medical staff working to save your life.The transplant team does not become involved with you until doctors
have determined that all possible efforts to save your life have failed.
5 If you need an organ transplant,your doctor will help you get on the national waiting list.Your name
will be added to a pool of names.When an organ donor becomes available,all the patients in the pool are
compared to that donor. Factors such as blood and tissue type, size of the organ, medical urgency（紧急）of
the patient's illness , time already spent on the waiting list, and distance between donor and recipient（接受
者）are considered.
Various factors are considered when deciding on_________.
A:donated organs
B:the national waiting list
C:a donor card
D:senior citizens
E:all possible efforts
F:the most suitable candidate
共用题干
Please Fasten Your Seatbelts
Severe turbulence（湍流）can kill aircraft passengers.Now,in test flights over the Rocky Mountains, NASA（美国航空航天局）engineers have successfully detected clear-air turbulence up to 10 seconds before an aircraft hits it.
Clear-air turbulence often catches pilots by surprise.Invisible to radar,it is difficult to forecast and can hurl（用力抛出去）passengers about the cabin.In December 1997 , one passenger died and a hundred others were injured when unexpected rough air caused a United Airlines flight over the Pacific to drop 300 meters in a few seconds.
However,passengers can avoid serious injury by fastening their seatbelts."It is the only antidote（对 策）for this sort of thing,"says Rod Bogue, project manager at NASA's Dryden Flight Research Center in Edwards,California.
The Center's new turbulence detector is based on lidar,or laser-radar.Laser pulses are sent ahead of the plane and these are then reflected back by particles in the air.The technique depends on the Doppler Effect（多普勒效应）.The wavelength of the light shifts according to the speed at which the particles are approaching.In calm air,the speed equals the plane's airspeed.But as the particles swirl（打漩） in rough air,their speed of approach increases or decreases rapidly.The rate of change in speed corresponds to the severity（激烈程度）of the turbulence.
In a series of tests that began last month,a research jet flew repeatedly into、 disturbed air over the mountain ridges（山脉）near Pueblo , Colorado.The lidar detector spotted turbulence between 3 and 8 kilometers ahead, and its forecasts of strength and duration corresponded closely with the turbulence that the plane encountered.
Bogue says that he had"a comfortable amount of time"to fasten his seatbelt.The researchers are planning to improve the lidar's range with a more powerful beam.The system could be installed on commercial aircraft in the next few years.
In December 1997,a United Airlines flight hit unexpected rough air______.
A:causing a lot of damage to the plane
B:throwing its passengers out of the cabin
C:resulting in heavy casualties
D:forcing the pilot to make an emergency landing
Please Fasten Your Seatbelts
Severe turbulence（湍流）can kill aircraft passengers.Now,in test flights over the Rocky Mountains, NASA（美国航空航天局）engineers have successfully detected clear-air turbulence up to 10 seconds before an aircraft hits it.
Clear-air turbulence often catches pilots by surprise.Invisible to radar,it is difficult to forecast and can hurl（用力抛出去）passengers about the cabin.In December 1997 , one passenger died and a hundred others were injured when unexpected rough air caused a United Airlines flight over the Pacific to drop 300 meters in a few seconds.
However,passengers can avoid serious injury by fastening their seatbelts."It is the only antidote（对 策）for this sort of thing,"says Rod Bogue, project manager at NASA's Dryden Flight Research Center in Edwards,California.
The Center's new turbulence detector is based on lidar,or laser-radar.Laser pulses are sent ahead of the plane and these are then reflected back by particles in the air.The technique depends on the Doppler Effect（多普勒效应）.The wavelength of the light shifts according to the speed at which the particles are approaching.In calm air,the speed equals the plane's airspeed.But as the particles swirl（打漩） in rough air,their speed of approach increases or decreases rapidly.The rate of change in speed corresponds to the severity（激烈程度）of the turbulence.
In a series of tests that began last month,a research jet flew repeatedly into、 disturbed air over the mountain ridges（山脉）near Pueblo , Colorado.The lidar detector spotted turbulence between 3 and 8 kilometers ahead, and its forecasts of strength and duration corresponded closely with the turbulence that the plane encountered.
Bogue says that he had"a comfortable amount of time"to fasten his seatbelt.The researchers are planning to improve the lidar's range with a more powerful beam.The system could be installed on commercial aircraft in the next few years.
In December 1997,a United Airlines flight hit unexpected rough air______.
A:causing a lot of damage to the plane
B:throwing its passengers out of the cabin
C:resulting in heavy casualties
D:forcing the pilot to make an emergency landing
共用题干
第二篇
Nuclear Power and Its Danger
Nuclear power's danger to health,safety,and even life itself can be summed up in one word:radiation.
Nuclear radiation has a certain mystery about it,partly because it cannot be detected by human senses.
It can't be seen or heard,or touched,or tasted,even though it may be all around us.There are other things
like that.For example,radio waves are all around us but we can't detect them,sense them,without a radio
receiver.Similarly,we can't sense radioactivity without a radiation detector. But unlike common radio waves,
nuclear radiation is not harmless to'human beings and other living things.
At very high levels,radiation can kill an animal or human being outright by killing masses of cells in
vital organs.But even the lowest level of radiation can do serious damage.There is no level of radiation that is
comnpletely safe.If the radiation does not hit anything important,the damage may not be significant.This is
the case when only a few cells are hit,and if they are killed outright.Your body will replace the dead cells
with healthy ones.But if the few cells are only damaged,and if they reproduce themselves,you may be in
trouble.They reproduce themselves in a deformed way.They can grow into cancer. Sometimes this does not
show up for many years.
There is another reason for the mystery of nuclear radiation.Serious damage can be done without the
victim being aware at the time that damage occurs. A person can be irradiated and feel fine,then die of cancer
five,ten,or twenty years later as a result.Or a child can be born weak or liable to serious illness as a result
of radiation absorbed by its grandparents.
Radiation can hurt us.We must know the truth.
Radiation can hurt us in the way that it can _______________.
A:kill large numbers of cells in main organs so as to cause death immediately
B:damage cells which may grow into cancer years later
C:affect the healthy growth of our offspring
D:all of the above
第二篇
Nuclear Power and Its Danger
Nuclear power's danger to health,safety,and even life itself can be summed up in one word:radiation.
Nuclear radiation has a certain mystery about it,partly because it cannot be detected by human senses.
It can't be seen or heard,or touched,or tasted,even though it may be all around us.There are other things
like that.For example,radio waves are all around us but we can't detect them,sense them,without a radio
receiver.Similarly,we can't sense radioactivity without a radiation detector. But unlike common radio waves,
nuclear radiation is not harmless to'human beings and other living things.
At very high levels,radiation can kill an animal or human being outright by killing masses of cells in
vital organs.But even the lowest level of radiation can do serious damage.There is no level of radiation that is
comnpletely safe.If the radiation does not hit anything important,the damage may not be significant.This is
the case when only a few cells are hit,and if they are killed outright.Your body will replace the dead cells
with healthy ones.But if the few cells are only damaged,and if they reproduce themselves,you may be in
trouble.They reproduce themselves in a deformed way.They can grow into cancer. Sometimes this does not
show up for many years.
There is another reason for the mystery of nuclear radiation.Serious damage can be done without the
victim being aware at the time that damage occurs. A person can be irradiated and feel fine,then die of cancer
five,ten,or twenty years later as a result.Or a child can be born weak or liable to serious illness as a result
of radiation absorbed by its grandparents.
Radiation can hurt us.We must know the truth.
Radiation can hurt us in the way that it can _______________.
A:kill large numbers of cells in main organs so as to cause death immediately
B:damage cells which may grow into cancer years later
C:affect the healthy growth of our offspring
D:all of the above
共用题干
Treating China's Online Addicts
Wang Yiming,21,is a self-confessed Internet addict,one of a growing number in China. He used to spend hours online each day,often going without food or sleep.His face is drawn and sallow. He said addiction changed his whole life:
"A month or two after I started surfing the Internet,I failed some of my school tests,but I was too afraid to tell my parents.When my parents found out,they were very angry."
"But I couldn't control my addiction.Friends were also telling me that I was on the net too long,but I thought:'It's my life,I can do what I want.'I became a real loner,was withdrawn,and wouldn't listen to anyone."
For help,Wang Yiming went to China's first Internet clinic,a low-rise,anonymous building in central Beijing. The clinic is part of a bigger addiction centre also treating those hooked on alcohol or drugs.The Internet addicts go on a two-week course involving medical treatment,psychological therapy,and daily workouts.
All 15 patients when I visited were young men一the main social group affected by this problem一and they all told a similar story of how their addiction to the net destroyed their lives.
Every day in China,more than 20 million youngsters go online to play games and hit the chat rooms,and that means that Internet addiction among young people is becoming a major issue here. The Chinese authorities have started to wake up to the seriousness of the problem with more articles in the papers highlighting the dangers of going online for too long.
Wang Yiming didn't want his life to be affected by others' opinion.
A:Right
B:Wrong
C:Not mentioned
Treating China's Online Addicts
Wang Yiming,21,is a self-confessed Internet addict,one of a growing number in China. He used to spend hours online each day,often going without food or sleep.His face is drawn and sallow. He said addiction changed his whole life:
"A month or two after I started surfing the Internet,I failed some of my school tests,but I was too afraid to tell my parents.When my parents found out,they were very angry."
"But I couldn't control my addiction.Friends were also telling me that I was on the net too long,but I thought:'It's my life,I can do what I want.'I became a real loner,was withdrawn,and wouldn't listen to anyone."
For help,Wang Yiming went to China's first Internet clinic,a low-rise,anonymous building in central Beijing. The clinic is part of a bigger addiction centre also treating those hooked on alcohol or drugs.The Internet addicts go on a two-week course involving medical treatment,psychological therapy,and daily workouts.
All 15 patients when I visited were young men一the main social group affected by this problem一and they all told a similar story of how their addiction to the net destroyed their lives.
Every day in China,more than 20 million youngsters go online to play games and hit the chat rooms,and that means that Internet addiction among young people is becoming a major issue here. The Chinese authorities have started to wake up to the seriousness of the problem with more articles in the papers highlighting the dangers of going online for too long.
Wang Yiming didn't want his life to be affected by others' opinion.
A:Right
B:Wrong
C:Not mentioned
共用题干
"Much of the sickness and death attributed_________(51)the major communicable diseases is in fact caused by malnutrition which makes the body less able to withstand infections when they strike",said Dr. Hiroshi Nakajima,Director-General of WHO,in his statement on the first day of the World Food Summit.
"At the same time,"he added,"in developing countries today,malnutrition is the cause of 174 million children under five years of age being________(52),and 230 million being stunted in their growth.Such_________(53)represent deprivation,suffering and wasted human potential __________(54)a scale that is unacceptable from every point of view. Whether we think in __________(55)of humanitarian concern,common justice or development needs,they demand a ___________(56),both from national governments and from international community."At the end of January 1996,98__________(57)had national plans of action for nutrition and 41 countries had one under preparation,in keeping with their___________(58)made at the International Conference on Nutrition in Rome in December 1992.
The global situation,__________(59),remains grim. It is now __________(60)that 6.6 million out of the estimated 12.2 million deaths_________(61)are among children under five.In some__________(62),such as sub-Saharan Africa and south Asia,stagnation （停滞）of nutritional improvement_________(63)with a rapid rise in population has result in an ________(64)increase in total number of malnourished children.Over 800 million people around the world still cannot_________(65)basic needs for energy and protein,more than two thousand million people lack essential micronutrients,and hundreds of millions suffer from diseases caused by unsafe food and unbalanced diets.
_________(54)
A:at
B:in
C:on
D:for
"Much of the sickness and death attributed_________(51)the major communicable diseases is in fact caused by malnutrition which makes the body less able to withstand infections when they strike",said Dr. Hiroshi Nakajima,Director-General of WHO,in his statement on the first day of the World Food Summit.
"At the same time,"he added,"in developing countries today,malnutrition is the cause of 174 million children under five years of age being________(52),and 230 million being stunted in their growth.Such_________(53)represent deprivation,suffering and wasted human potential __________(54)a scale that is unacceptable from every point of view. Whether we think in __________(55)of humanitarian concern,common justice or development needs,they demand a ___________(56),both from national governments and from international community."At the end of January 1996,98__________(57)had national plans of action for nutrition and 41 countries had one under preparation,in keeping with their___________(58)made at the International Conference on Nutrition in Rome in December 1992.
The global situation,__________(59),remains grim. It is now __________(60)that 6.6 million out of the estimated 12.2 million deaths_________(61)are among children under five.In some__________(62),such as sub-Saharan Africa and south Asia,stagnation （停滞）of nutritional improvement_________(63)with a rapid rise in population has result in an ________(64)increase in total number of malnourished children.Over 800 million people around the world still cannot_________(65)basic needs for energy and protein,more than two thousand million people lack essential micronutrients,and hundreds of millions suffer from diseases caused by unsafe food and unbalanced diets.
_________(54)
A:at
B:in
C:on
D:for
共用题干
第三篇
Oil and Economy
Could the bad old days of economic decline be about to return?Since OPEC agreed to supplycuts in March,the price of crude oil has jumped to almost $26 a barrel,up from less than$10 last December. This near-tripling of oil prices calls up scary memories of the 1973 oil shock,when prices quadrupled,and 1979一1980,when they also almost tripled.Both previous shocks resulted in double-digit inflation and global economic decline.So where are the headlines warning of gloom and doom this time?
The oil price was given another push up this week when Iraq suspended oil exports.Strengthening economic growth,at the same time as winter grips the northern hemisphere,could push the price higher still in the short term.
Yet there are good reasons to expect the economic consequences now to be less severe than in the l970s.In most countries the cost of crude oil now accounts for a smaller share of the price of petrol than it did in the l970s.In Europe,taxes account for up to four-fifths of the retail price,so even quite big changes in the price of crude have a more muted effect on pump prices than in the past.
Rich economies are also less dependent on oil than they were,and so less sensitive to swings in the oil price.Energy conservation,a shift to other fuels and a decline in the importance of heavy, energy-intensive industries have reduced oil consumption.Software,consultancy and mobile telephones use far less oil than steel or car production.For each dollar of GDP(inconstant prices)in rich economies now use nearly 50%less oil than in 1973.The OECD estimates in its latest Economic Outlook that,if oil prices averaged $22 a barrel for a full year,compared with$13 in 1998,this would increase the oil import bill in rich economies by only 0.25％～0.5%of GDP.That is less than one-quarter of the income loss in 1974 or 1980. On the other hand,oil-importing emerging economies一to which heavy industry has shifted一have become more energy-intensive,and so could be more seriously squeezed.
One more reason not to lose sleep over the rise in oil prices is that,unlike the rises in the 1970s,it has not occurred against the background of general commodity-price inflation and global excess demand.A sizable portion of the world is only just emerging from economic decline.The Economist's commodity price index is broadly unchanging from a year ago.In 1973 commodity prices jumped by 70%,and in 1979 by almost 30%.
From the text we can see that the writer seems_______.
A:optimistic
B:sensitive
C:gloomy
D:scared
第三篇
Oil and Economy
Could the bad old days of economic decline be about to return?Since OPEC agreed to supplycuts in March,the price of crude oil has jumped to almost $26 a barrel,up from less than$10 last December. This near-tripling of oil prices calls up scary memories of the 1973 oil shock,when prices quadrupled,and 1979一1980,when they also almost tripled.Both previous shocks resulted in double-digit inflation and global economic decline.So where are the headlines warning of gloom and doom this time?
The oil price was given another push up this week when Iraq suspended oil exports.Strengthening economic growth,at the same time as winter grips the northern hemisphere,could push the price higher still in the short term.
Yet there are good reasons to expect the economic consequences now to be less severe than in the l970s.In most countries the cost of crude oil now accounts for a smaller share of the price of petrol than it did in the l970s.In Europe,taxes account for up to four-fifths of the retail price,so even quite big changes in the price of crude have a more muted effect on pump prices than in the past.
Rich economies are also less dependent on oil than they were,and so less sensitive to swings in the oil price.Energy conservation,a shift to other fuels and a decline in the importance of heavy, energy-intensive industries have reduced oil consumption.Software,consultancy and mobile telephones use far less oil than steel or car production.For each dollar of GDP(inconstant prices)in rich economies now use nearly 50%less oil than in 1973.The OECD estimates in its latest Economic Outlook that,if oil prices averaged $22 a barrel for a full year,compared with$13 in 1998,this would increase the oil import bill in rich economies by only 0.25％～0.5%of GDP.That is less than one-quarter of the income loss in 1974 or 1980. On the other hand,oil-importing emerging economies一to which heavy industry has shifted一have become more energy-intensive,and so could be more seriously squeezed.
One more reason not to lose sleep over the rise in oil prices is that,unlike the rises in the 1970s,it has not occurred against the background of general commodity-price inflation and global excess demand.A sizable portion of the world is only just emerging from economic decline.The Economist's commodity price index is broadly unchanging from a year ago.In 1973 commodity prices jumped by 70%,and in 1979 by almost 30%.
From the text we can see that the writer seems_______.
A:optimistic
B:sensitive
C:gloomy
D:scared
共用题干
Eat to Live
A meager diet may give you health and long life,but it's not much fun-and it might not even be necessary.We may be able to hang on to most of that youthful vigor even if we don't start to diet until old age.
Stephen Spindler and his colleagues from the University of California at Riverside have found that some of an elderly mouse's liver genes can be made to behave as they did when the mouse was young simply by limiting its food for four weeks.The genetic rejuvenation won't reverse other damage caused by time for the mouse,but could help its liver metabolize drugs or get rid of toxins.
Spindler's team fed three mice a normal diet for their whole lives,and fed another three on half-rations.Three more mice were switched from the normal diet to half-feed for a month when they were 34 months old-equivalent to about 70 human years.
The researchers checked the activity of 11,000 genes from the mouse livers,and found that-46 changed with age in the normally fed mice.The changes were associated with things like inflammation and free radical production-probably bad news for mouse health .In the mice that had dieted all their lives,27 of those 46 genes continued to behave like young genes. But the most surprising finding was that the mice that only started dieting in old age also benefited from 70 percent of these gene changes.
"This is the first indication that these effects kick in pretty quickly,"says Huber Warner from the National Institute on Aging near Washington D.C.
No one yet knows if calorie restriction works in people as it does in mice,but Spindler is hopeful."There's attracting and tempting evidence out there that it will work,"he says.
If it does work in people,there might be good reasons for rejuvenating the liver. As we get ol- der,our bodies are less efficient at metabolizing drugs,for example.A brief period of time of die- ting,says Spindler,could be enough to make sure a drug is effective.
But Spindler isn't sure the trade-off is worth it."The mice get less disease,they live longer,but they're hungry,"he says."Even seeing what a diet does,it's still hard to go to a restaurant and say:‘I can only eat half of that.’"
Spindler hopes we soon won't need to diet at all.His company,Lifespan Genetics in California,is looking for drugs that have the effects of calorie restriction.
According to the passage,which of the following is NOT true?
A: Eating less than usual might make us live longer.
B:If we go on a diet when old,we may keep healthy.
C: Dieting might not be needed.
D: We have to begin dieting since childhood.
Eat to Live
A meager diet may give you health and long life,but it's not much fun-and it might not even be necessary.We may be able to hang on to most of that youthful vigor even if we don't start to diet until old age.
Stephen Spindler and his colleagues from the University of California at Riverside have found that some of an elderly mouse's liver genes can be made to behave as they did when the mouse was young simply by limiting its food for four weeks.The genetic rejuvenation won't reverse other damage caused by time for the mouse,but could help its liver metabolize drugs or get rid of toxins.
Spindler's team fed three mice a normal diet for their whole lives,and fed another three on half-rations.Three more mice were switched from the normal diet to half-feed for a month when they were 34 months old-equivalent to about 70 human years.
The researchers checked the activity of 11,000 genes from the mouse livers,and found that-46 changed with age in the normally fed mice.The changes were associated with things like inflammation and free radical production-probably bad news for mouse health .In the mice that had dieted all their lives,27 of those 46 genes continued to behave like young genes. But the most surprising finding was that the mice that only started dieting in old age also benefited from 70 percent of these gene changes.
"This is the first indication that these effects kick in pretty quickly,"says Huber Warner from the National Institute on Aging near Washington D.C.
No one yet knows if calorie restriction works in people as it does in mice,but Spindler is hopeful."There's attracting and tempting evidence out there that it will work,"he says.
If it does work in people,there might be good reasons for rejuvenating the liver. As we get ol- der,our bodies are less efficient at metabolizing drugs,for example.A brief period of time of die- ting,says Spindler,could be enough to make sure a drug is effective.
But Spindler isn't sure the trade-off is worth it."The mice get less disease,they live longer,but they're hungry,"he says."Even seeing what a diet does,it's still hard to go to a restaurant and say:‘I can only eat half of that.’"
Spindler hopes we soon won't need to diet at all.His company,Lifespan Genetics in California,is looking for drugs that have the effects of calorie restriction.
According to the passage,which of the following is NOT true?
A: Eating less than usual might make us live longer.
B:If we go on a diet when old,we may keep healthy.
C: Dieting might not be needed.
D: We have to begin dieting since childhood.