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Batteries Built by Viruses
What do chicken pox,the common cold,the flu,and AIDS have in common?They're all diseases caused by viruses,tiny microorganisms that can pass from person to person. It's no wonder that when most people think about viruses,finding ways to steer clear of viruses is what's on people's minds.
Not everyone runs from the tiny disease carriers,though. In Cambridge,Massachu- setts,scientists have discovered that some viruses can be helpful in an unusual way. They are putting viruses to work,teaching them to build some of the world's smallest rechargeable batteries.
Viruses and batteries may seem like an unusual pair,but they're not so strange for engi-neer Angela Beicher,who first came up with the idea. At the Massachusetts Institute of
Technology(MIT)in Cambridge,she and her collaborators bring together different areas of science in new ways.In the case of the virus-built batteries,the scientists combine what they know about biology,technology and production techniques.
Beicher's team includes Paula Hammond,who helps put together the tiny batteries,and
Yet-Ming Chiang,an expert on how to store energy in the form of a battery.“We're working on things we traditionally don't associate with nature，”says Hammond.
Many batteries are already pretty small. You can hold A,C and D batteries in your hand. The coin-like batteries that power watches are often smaller than a penny. However, every year,new electronic devices like personal music players or cell phones get smaller than the year before. As these devices shrink,ordinary batteries won't be small enough to fit in-side.
The ideal battery will store a lot of energy in a small package. Right now,Belcher's model battery,a metallic disk completely built by viruses,looks like a regular watch battery. But inside,its components are very small一so tiny you can only see them with a powerful microscope.
How small are these battery parts?To get some idea of the size,pluck one hair from your head. Place your hair on a piece of white paper and try to see how wide your hair is一 pretty thin,right?Although the width of each person's hair is a bit different,you could probably fit about 10 of these virus-built battery parts,side to side,across one hair. These micro-batteries may change the way we look at viruses.
How tiny is one battery part?
A: Its width is one tenth of a hair.
B: It equals the width of a hair.
C: It is as thin as a piece of paper.
D: Its width is too tiny to measure.
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第二篇
Explorer of the Extreme Deep
Oceans cover more than two-thirds of our planet.Yet,just a small fraction of the underwater world has been explored.Now,Scientists at the Woods Hole Oceanographic Institution(WHOI)in Massachusetts are building an underwater vehicle that will carry explorers as deep as 6,500 meters (21,325.5 feet).The new machine,known as a manned submersible or human-operated vehicle (HOV),will replace another one named Alvin which has an amazing record of discovery,playing a key role in various important and famous undersea expeditions.Alvin has been operating for 40 years but can go down only 4,500 meters(14,763.8 feet).It's about time for an upgrade,WHOI researchers say.
Alvin was launched in 1964.Since then,Alvin has worked between 200 and 250 days a year, says Daniel Fornari,a marine geologist and director of the Deep Ocean Exploration Institute at WHOI.During its lifetime,Alvin has carried some 12,000 people on a total of more than 3,000 dives.A newer,better versions of Alvin is bound to reveal even more surprises about a world that is still full of mysteries,Fornari says.It might also make the job of exploration a little easier."We take so much for granted on land."Fornari says."We can walk around and see with our eyes how big things are.We can see colors,special arrangements."
Size-wise,the new HOV will be similar to Alvin.It'll be about 37 feet long. The setting area inside will be a small sphere,about 8 feet wide,like Alvin.It'll carry a pilot and two passengers.It will be just as maneuverable.In most other ways,it will give passengers more opportunities to enjoy the view,for one thing. Alvin has only three windows,the new vehicle will have five,with more overlap so that the passengers and the pilot can see the same thing.
Alvin can go up and down at a rate of 30 meters every second,and its maximum speed is 2 knots(about 2.3 miles per hour),while the new vehicle will be able to ascend and descend at 44 meters per second.It'll reach speeds of 3 knots,or 3.5 miles per hour.
What is Alvin?
A:A research institute.
B:A transporting vehicle.
C:A submersible.
D:A scientist.
第二篇
Explorer of the Extreme Deep
Oceans cover more than two-thirds of our planet.Yet,just a small fraction of the underwater world has been explored.Now,Scientists at the Woods Hole Oceanographic Institution(WHOI)in Massachusetts are building an underwater vehicle that will carry explorers as deep as 6,500 meters (21,325.5 feet).The new machine,known as a manned submersible or human-operated vehicle (HOV),will replace another one named Alvin which has an amazing record of discovery,playing a key role in various important and famous undersea expeditions.Alvin has been operating for 40 years but can go down only 4,500 meters(14,763.8 feet).It's about time for an upgrade,WHOI researchers say.
Alvin was launched in 1964.Since then,Alvin has worked between 200 and 250 days a year, says Daniel Fornari,a marine geologist and director of the Deep Ocean Exploration Institute at WHOI.During its lifetime,Alvin has carried some 12,000 people on a total of more than 3,000 dives.A newer,better versions of Alvin is bound to reveal even more surprises about a world that is still full of mysteries,Fornari says.It might also make the job of exploration a little easier."We take so much for granted on land."Fornari says."We can walk around and see with our eyes how big things are.We can see colors,special arrangements."
Size-wise,the new HOV will be similar to Alvin.It'll be about 37 feet long. The setting area inside will be a small sphere,about 8 feet wide,like Alvin.It'll carry a pilot and two passengers.It will be just as maneuverable.In most other ways,it will give passengers more opportunities to enjoy the view,for one thing. Alvin has only three windows,the new vehicle will have five,with more overlap so that the passengers and the pilot can see the same thing.
Alvin can go up and down at a rate of 30 meters every second,and its maximum speed is 2 knots(about 2.3 miles per hour),while the new vehicle will be able to ascend and descend at 44 meters per second.It'll reach speeds of 3 knots,or 3.5 miles per hour.
What is Alvin?
A:A research institute.
B:A transporting vehicle.
C:A submersible.
D:A scientist.
共用题干
The Biology of Music
Humans use music as a powerful way to communicate.It may also play an important role in love.But what is music,and how does it work its magic?Science does not yet have all the answers.
What are two things that make humans different from animals?One is language,and the other is music.It is true that some animals can sing(and many birds sing better than a lot of people).However,the songs of animals,such as birds and whales,are very limited.It is also true that humans,not animals,have developed musical instruments.
Music is strange stuff.It is clearly different from language.However,people can use music to communicate things-especially their emotions.When music is combined with speech in a song,it is a very powerful form of communication.But,biologically speaking,what is music?
If music is truly different from speech,then we should process music and language in different parts of the brain.The scientific evidence suggests that this is true.
Sometimes people who , suffer brain damage lose their ability to process language.However,they don't automatically（自动地）lose their musical abilities.For example , Vissarion Shebalin , a Russian composer , had a stroke（中风）in 1953.It injured the left side of his brain.He could no longer speak or understand speech.He could,however,still compose music until his death ten years later.On the other hand,sometimes strokes cause people to lose their musical ability,but they can still speak and understand speech.This shows that the brain processes music and language separately.
By studying the physical effects of music on the body,scientists have also learned a lot about how music influences the emotions.But why does music have such a strong effect on us?That is a harder question to answer.Geoffrey Miller,a researcher at University College,London,thinks that music and love have a strong connection.Music requires special talent,practice,and physical ability.That's why it may be a way of showing your fitness to be someone's mate.For example,singing in tune or playing a musical instrument requires fine muscular control.You also need a good memory to remember the notes（音符）.And playing or singing those notes correctly suggests that your hearing is in excellent condition.Finally,when a man sings to the woman he loves(or vice versa),it may be a way of showing off.
However,Miller's theory still doesn't explain why certain combinations of sounds influence our emotions so deeply.For scientists,this is clearly an area that needs further research.
The author doesn't suggest that______.
A:music requires special talent
B:music requires practice
C:music requires psychological ability
D:music requires physical ability
The Biology of Music
Humans use music as a powerful way to communicate.It may also play an important role in love.But what is music,and how does it work its magic?Science does not yet have all the answers.
What are two things that make humans different from animals?One is language,and the other is music.It is true that some animals can sing(and many birds sing better than a lot of people).However,the songs of animals,such as birds and whales,are very limited.It is also true that humans,not animals,have developed musical instruments.
Music is strange stuff.It is clearly different from language.However,people can use music to communicate things-especially their emotions.When music is combined with speech in a song,it is a very powerful form of communication.But,biologically speaking,what is music?
If music is truly different from speech,then we should process music and language in different parts of the brain.The scientific evidence suggests that this is true.
Sometimes people who , suffer brain damage lose their ability to process language.However,they don't automatically（自动地）lose their musical abilities.For example , Vissarion Shebalin , a Russian composer , had a stroke（中风）in 1953.It injured the left side of his brain.He could no longer speak or understand speech.He could,however,still compose music until his death ten years later.On the other hand,sometimes strokes cause people to lose their musical ability,but they can still speak and understand speech.This shows that the brain processes music and language separately.
By studying the physical effects of music on the body,scientists have also learned a lot about how music influences the emotions.But why does music have such a strong effect on us?That is a harder question to answer.Geoffrey Miller,a researcher at University College,London,thinks that music and love have a strong connection.Music requires special talent,practice,and physical ability.That's why it may be a way of showing your fitness to be someone's mate.For example,singing in tune or playing a musical instrument requires fine muscular control.You also need a good memory to remember the notes（音符）.And playing or singing those notes correctly suggests that your hearing is in excellent condition.Finally,when a man sings to the woman he loves(or vice versa),it may be a way of showing off.
However,Miller's theory still doesn't explain why certain combinations of sounds influence our emotions so deeply.For scientists,this is clearly an area that needs further research.
The author doesn't suggest that______.
A:music requires special talent
B:music requires practice
C:music requires psychological ability
D:music requires physical ability
Traffic reaches its rush hour between 8:00 and 9:00 in the morning.
A:border
B: goal
C: peak
D: level
A:border
B: goal
C: peak
D: level
共用题干
Tightened Visa Regulations
According to South Korea's new visa regulations,native speakers of English in South Korea will be required to undergo criminal record checks,medical and drug tests,provide sealed academic transcripts（成绩单）and have their university diplomas inspected,The Korea Times has reported.The tightened regulations will affect an estimated 17,000 foreigners that hold E-2 visas specifically for foreign language teachers.
The most controversial requirement is that English teachers residing（居住）outside South Korea will have to have an interview at a South Korean Embassy before taking up their teaching posts. For applicants living in remote areas in Canada,Australia or the US,this is an additional travel burden .Meanwhile,foreign teachers currently living in South Korea must leave the country after their one-year contracts and renew their visas by visiting a neighboring country and return without additional documentation（文件证据）.
The visa changes are a reaction to public concern about the suitability of some foreign teachers .A report from the South Korean Ministry of Education and Human Resources Development shows between 2001 and August of this year,1,481 foreign language teachers have been caught for a range of offenses including forged（伪造的）degrees , visa violations and general lawbreak-ing.
But the changes are likely to slow up the supply of teachers to South Korea's English language education sector. According to Michael Duffy,manager of a teacher placement service in South Korea,applicants have to spend a few hundred dollars and several months on getting affidavits（书面陈述书）for documents. " South Korea has put up too many hoops（圈）to jump through,"he said,adding that foreigners would seek work elsewhere.Most foreigners wonder if the experience of working in South Korea will be worth the burden of the paper work and increasing restrictions."I don't think(South)Korea has thought this through."Said Scott Mclnnis,a Canadian teacher based in Incheon near Seoul."This is a reactionary move by the government that will have strong implications for the EFL community."
As part of the efforts to ease the discontent（不满）,the South Korean Ministry of Justice has granted a three-month grace period for current E-2 visa holders to prepare the necessary docu- ments.
Which of the following is NOT required of an E-2 visa applicant?
A: To pass a Korean language test.
B: To undergo a medical test.
C: To provide sealed school reports.
D: To undergo a drug test.
Tightened Visa Regulations
According to South Korea's new visa regulations,native speakers of English in South Korea will be required to undergo criminal record checks,medical and drug tests,provide sealed academic transcripts（成绩单）and have their university diplomas inspected,The Korea Times has reported.The tightened regulations will affect an estimated 17,000 foreigners that hold E-2 visas specifically for foreign language teachers.
The most controversial requirement is that English teachers residing（居住）outside South Korea will have to have an interview at a South Korean Embassy before taking up their teaching posts. For applicants living in remote areas in Canada,Australia or the US,this is an additional travel burden .Meanwhile,foreign teachers currently living in South Korea must leave the country after their one-year contracts and renew their visas by visiting a neighboring country and return without additional documentation（文件证据）.
The visa changes are a reaction to public concern about the suitability of some foreign teachers .A report from the South Korean Ministry of Education and Human Resources Development shows between 2001 and August of this year,1,481 foreign language teachers have been caught for a range of offenses including forged（伪造的）degrees , visa violations and general lawbreak-ing.
But the changes are likely to slow up the supply of teachers to South Korea's English language education sector. According to Michael Duffy,manager of a teacher placement service in South Korea,applicants have to spend a few hundred dollars and several months on getting affidavits（书面陈述书）for documents. " South Korea has put up too many hoops（圈）to jump through,"he said,adding that foreigners would seek work elsewhere.Most foreigners wonder if the experience of working in South Korea will be worth the burden of the paper work and increasing restrictions."I don't think(South)Korea has thought this through."Said Scott Mclnnis,a Canadian teacher based in Incheon near Seoul."This is a reactionary move by the government that will have strong implications for the EFL community."
As part of the efforts to ease the discontent（不满）,the South Korean Ministry of Justice has granted a three-month grace period for current E-2 visa holders to prepare the necessary docu- ments.
Which of the following is NOT required of an E-2 visa applicant?
A: To pass a Korean language test.
B: To undergo a medical test.
C: To provide sealed school reports.
D: To undergo a drug test.
共用题干
第二篇
Depression
Although the stigma（耻辱）once associated with mental illness has gradually gone away in recent years,most of the Americans who have clinical depression still don't get treated for it partly because many are too embarrassed to go to a psychologist. In fact,the majority of depressed people who seek professional help turn first not to a psychologist but to their primary care physician.
But do regular doctors really know how to identify depression?A large new scientific review suggests they don't. In a review of 41 previous studies,the authors found that general practitioners make frequent mistakes,missing true cases of depression about half the time and incorrectly diagnosing it in 19%of healthy people.
Alex Mitchell,Amol Vaze and Sanjay Rao of Leicester General Hospital in the U.K. estimate that about 1 in 5 people in developed nations will experience depression in their lifetime.That means that among a general patient population of 100,about 20 will develop the condition,but the typical doctor will find it in only 10 of those who have it. And among the 80 healthy people,the doctor will incorrectly identify depression in 15.
This is significant because depression can make the patient and his or her family weak.Depression also carries an enormous social burden,leading to missed work days,loss of productivity and increases in health-care spending. Further,those misdiagnosed with depression may end up being prescribed medicine that not only costs a lot but can have serious side effects.
The various studies that Mitchell,Vaze and Rao reviewed used different methods to verify whether doctors had missed depression in their patients.Virtually all the studies pointed to the same conclusion:general physicians aren't very good at recognizing the most common mental illness in the world.
Why?One reason is that the typical doctor visit is quite short,usually no longer than 15 minutes.It's hard for patients to open up about their symptoms during that brief period.Doctors should spend more time or schedule follow-up appointments with patients they suspect have depression, which would dramatically increase the rate of accurate diagnoses.
In a new scientific review,the researchers found that________.
A:psychologists often miss the true case of depression
B:general physicians often make wrong judgment of depression
C:most people will experience depression in their lifetime
D:primary care physicians are not qualified doctors
第二篇
Depression
Although the stigma（耻辱）once associated with mental illness has gradually gone away in recent years,most of the Americans who have clinical depression still don't get treated for it partly because many are too embarrassed to go to a psychologist. In fact,the majority of depressed people who seek professional help turn first not to a psychologist but to their primary care physician.
But do regular doctors really know how to identify depression?A large new scientific review suggests they don't. In a review of 41 previous studies,the authors found that general practitioners make frequent mistakes,missing true cases of depression about half the time and incorrectly diagnosing it in 19%of healthy people.
Alex Mitchell,Amol Vaze and Sanjay Rao of Leicester General Hospital in the U.K. estimate that about 1 in 5 people in developed nations will experience depression in their lifetime.That means that among a general patient population of 100,about 20 will develop the condition,but the typical doctor will find it in only 10 of those who have it. And among the 80 healthy people,the doctor will incorrectly identify depression in 15.
This is significant because depression can make the patient and his or her family weak.Depression also carries an enormous social burden,leading to missed work days,loss of productivity and increases in health-care spending. Further,those misdiagnosed with depression may end up being prescribed medicine that not only costs a lot but can have serious side effects.
The various studies that Mitchell,Vaze and Rao reviewed used different methods to verify whether doctors had missed depression in their patients.Virtually all the studies pointed to the same conclusion:general physicians aren't very good at recognizing the most common mental illness in the world.
Why?One reason is that the typical doctor visit is quite short,usually no longer than 15 minutes.It's hard for patients to open up about their symptoms during that brief period.Doctors should spend more time or schedule follow-up appointments with patients they suspect have depression, which would dramatically increase the rate of accurate diagnoses.
In a new scientific review,the researchers found that________.
A:psychologists often miss the true case of depression
B:general physicians often make wrong judgment of depression
C:most people will experience depression in their lifetime
D:primary care physicians are not qualified doctors