题目内容
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How tiny is one battery part？ 查看材料
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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更多“How tiny is one battery part？ …”相关的问题
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.
The scientists made the deduction that the Iceman
A．was probably in some kind of a battle．
B．was hit in the shoulder by an arrowhead．
C．had got a wound on the back of his head．
D．had a tiny hole in his skin causing his death．
请根据短文的内容，回答题。
Batteries Built by Viruses
What do chicken pox, the common cold, the flu, and AIDS have in common？ They&39;re all disease caused by viruses, tiny microorganisms that can pass from person to person. It&39;s no wonder that when most people think about viruses, finding ways to steer clear of viruses is what&39;s on people&39;s minds.＜br＞
Not everyone runs from the tiny disease carriers, though. In Cambridge, Massachusetts,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&39;s smallest rechargeable batteries.＜br＞
Viruses and batteries may seem like an unusual pair, but they&39;re not so strange for engineer Angela Belcher, who first came up with5 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.＜br＞
Belcher&39;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&39;re working on things we traditionally don&39;t associate with nature," says Hammond.＜br＞
Many batteries are already pretty small. You can hold A, C and D batteries6 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 bakeries won&39;t be small enough to fit inside.＜br＞
The ideal battery will store a lot of energy in a small package. Right now, Belcher&39;s model battery, a metallic disk completely built by viruses, looks like a regular watch battery. But inside,its components are very small-so tiny you can only see them with a powerful microscope.＜br＞
How small are these battery parts？ To get some idea of the size, pluck one hair from your head.＜br＞
Place your hair on a piece of white paper and try to see how wide your hair is-pretty thin, right？＜br＞
Although the width of each person&39;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 microbatteries may change the way we look at viruses7.
According to the first paragraph people try to __________. 查看材料
A.kill microorganisms related to chicken pox， the flu， etc
B.keep themselves away from viruses because they are invisible
C.stay away from viruses because they are causes of various diseases
D.cure themselves of virus-related diseases by taking medicines
It was strange to feel my past life almost __6__ away as I entered this brand-new phase of my life. I didn’t know how to __7__ myself during my first couple of months at Penn because everything that defined me was back in California. I felt __8__ from my college friends because they only knew the college me. How could they really know me without knowing what Mission Boulevard looked like late at night with the Niles hills in the background？ How could they know me without knowing the friends who I had __9__ to Japan with or the friends I had gone to school with since kindergarten？ How could they know me if they hadn’t met my family？ How could they know me, or I them, if we didn’t know one another’s __10__ experiences？
A. drop B. journeyed C. unique D. define
E. complex F. realizing G. disconnected H. self-defining
I. drifted J. lying K. transition L. adjusted
M. fast-moving N. transported O. lack
A.covered
B.enclosed
C.surrounded
阅读材料，回答题。
How does Science Proceed？
How exactly does science work？ How do scientists go about "doing" science？ Ordinarily we think science proceeds in a straightforward way. Ideally, scientists make observations, formulate hypotheses, and test those hypotheses by making further observations. When there is difference between what is observed and what is predicted by the hypothesis, the hypothesis is reviewed. Science proceeds in this way, which is a gradual method of finding the best fit between observation and prediction.
But this idealized version of how one "does" science is naive.Although science demands proof that observations made by one observer be observable by other observers using the same methods.It is by no means clear that even when confronted with identical phenomena different observers will report identical observations.
And it is most certain that, even if the same observations are made, the conclusions as to the meaning of the observations frequently differ.
The fact is that all of us scientists included, see differently. Variations in human perception are well known and have been studied extensively. Distortions in perceptions are frequently seen among observers, even though they may be in identical settings viewing identical phenomena. A documented misperception from history can be found in the experience of Darwin.His ship, Beagle, after anchoring off the Patagonian coast, sent off a landing party in small rowboats. Amazingly, the Patagonian natives watching from shore were blind to the Beagle, but could easily see the tiny rowboats. They have no prior experience of huge sailing ships, but small rowing vessels were an everyday part of their life. Rowboats fit their model of the world but huge ships did not.Their model determined their perceptions.
Our ideas that science proceeds on an utterly objective and straightforward basis ignores the distortions of reality imposed by our own perceptual apparatus. In many cases we see what we have been trained to see, what we are used to seeing. If a subject is fitted with special glasses that are designed to invert the visual field, at first the subject sees everything upside down. After a period of time, as the glasses continue to be worn, a correction is made by our perceptual mechanism and the image is flipped, so that the world once again appears erect.
What is the main idea of the passage？ 查看材料
A.The research methods used by scientists
B.Observation and human perception variation
C.The relation between hypothesis and observation
D.The human perceptual mechanism
In the ancient world, as in today, most boys played with some kinds of toys and most girls with another. In societies where social roles are rigidly determined, boys pattern their play after the activities of their fathers and girls after the tasks of their mothers. This is true because boys and girls are being prepared, even in play to step into the roles and responsibilities of the adult world.
What is remarkable about the history of toys is not so much how they changed over the centuries but how much they have remained the same. The changes have been mostly in terms of craftsmanship, mechanics and technology. It is the universality of toys with regard to their development in all parts of the world and their persistence to the present that is amazing. In Egypt, the America, China, Japan and among the Arctic pole, generally the same kinds of toys appeared. Variations depended on local customs and ways of life because toys imitate their surroundings. Nearly every civilization had dolls, little weapons, toy soldiers, tiny animals and vehicles.
Because toys can be generally regarded as a kind of art form, they have not been subject to technological leaps that characterize inventions for adult use. The progress from the wheel to the ox cart to the automobile is a direct line of ascent(进步). The progress from a rattle (波浪鼓) used by a baby in 3000 B. C. to one used by an infant to day, however, is not characterized by inventiveness. Each rattle is the product of the artistic tastes of the times and subject to the limitations of available materials.
The reason why the toys most boys play with are different from those that girls play with is that ______.
A．their social roles are rigidly determined
B．most boys would like to follow their fathers' professions
C．boys like to play with their fathers while girls with their mothers
D．they like challenging activities
A.overviewed
B.outlooked
C.overlooked
D.oversaw
Scientists have found that there are three distinct stages in a mosquito's assault. Stage one is at fifty feet away, when the insect first smells a man or animal to bite. Stage two is thought to come into operation about twenty-five feet from the target, when the insect becomes guided by the carbon dioxide breathed out by the intended victim. Stage three is when the mosquito is only a matter of inches from its prey: the warmth and moisture given off by the victim is the final clue. The researchers then examined how repellents (驱虫剂) interfere with its three-stage attack. They found repellents act more subtly than by just giving off a nasty smell. A Canadian researcher says that repellents appear to confuse mosquitoes first when it is following the carbon dioxide and second during the find approach, where the warmth and moisture aren't the insect's guide.
Air pervaded by one of the many chemical repellents stops the mosquito reacting to the victim's carbon dioxide, anti the repellent seems to affect the tiny hairs with which the insect senses moisture in the air. The sensors are blocked so that the insect does not know when it is flying through a moist current, or the sensors are made to send the wrong signals.
One positive suggestion from the researchers followed the discovery that mosquitoes on the hunt tend to fly very close to the ground. A dense screen of trees around a village may keep mosquitoes at bay.
The experts also agree that mosquitoes seem to prefer some people to others, but they don't know why.
The phrase "homes in on its target" (Sentence 1, Para. 1) in the context means ______.
A．find its way to the intended victim
B．move towards the prey
C．set off for the target
D．aim at the victim
Cream and butter contain pretty much the same substances, so why cream should sour much faster has been a mystery. Both are emulsions—tiny globules (小球体) of one liquid evenly distributed throughout another. The difference lies in what’s in the globules and what’s in the surrounding liquid, says Brocklehurst, who led the investigation.
In cream, fatty globules drift about in a sea of water. In butter, globules of a watery solution are locked away in a sea of fat. The bacteria which make the food go bad prefer to live in the watery regions of the mixture. “This means that in cream, the bacteria are free to grow throughout the mixture,” he says.
When the situation is reversed, the bacteria are locked away in compartments (隔仓室) buried deep in the sea of fat. Trapped in this way, individual colonies cannot spread and rapidly run out of nutrients (养料). They also slowly poison themselves with their waste products. “In butter, you get a self-limiting system which stops the bacteria growing,” says Brocklehurst.
The researchers are already working with food companies keen to see if their products can be made resistant to bacterial attack through alterations to the food’s structure. Brocklehurst believes it will be possible to make the emulsions used in salad cream, for instance, more like that in butter. The key will be to do this while keeping the salad cream liquid and not turning it into a solid lump.
第36题：The significance of Brocklehurst’s research is that ________.
A) it suggested a way to keep some foods fresh without preservatives
B) it discovered tiny globules in both cream and butter
C) it revealed the secret of how bacteria multiply in cream and butter
D) it found that cream and butter share the same chemical composition
