单选题 .  SECTION A  MULTIPLE-CHOICE QUESTIONS
    In this section there are several passages followed by ten multiple-choice questions. For each question, there are four suggested answers marked A, B, C and D. Choose the one that you think is the best answer and mark your answers on ANSWER SHEET TWO.
    Passage One
    Something incredible is happening in a lab at Duke University's Center for Neuroengineering—though, at first, it's hard to see just what it is. A robot arm swings from side to side, eerily lifelike, as if it were trying to snatch invisible flies out of the air. It pivots around and straightens as it extends its mechanical hand. The hand clamp shuts and squeezes for a few seconds, then relaxes its grip and pulls back to shoot out again in a new direction. OK, nothing particularly astonishing here—robot arms, after all, do everything from building our cars to sequencing our DNA. But those robot arms are operated by software; the arm at Duke follows commands of a different sort. To see where those commands are coming from, you have to follow a tangled trail of cables out of the lab and down the hall to another, smaller room.
    Inside this room sits a motionless macaque monkey(短尾猿).
    The monkey is strapped in a chair, staring at a computer screen. On the screen a black dot moves from side to side; when it stops, a circle widens around it. You wouldn't know just from watching, but that dot represents the movements of the arm in the other room. The circle indicates the squeezing of its robotic grip; as the force of the grip increases, the circle widens. In other words, the dot and the circle are responding to the robot arm's movements. And the arm? It's being directed by the monkey.
    Did I mention the monkey is motionless?
    Take another look at those cables: They snake into the back of the computer and then out again, terminating in a cap on the monkey's head, where they receive signals from hundreds of electrodes buried in its brain. The monkey is directing the robot with its thoughts.
    For decades scientists have pondered, speculated on, and pooh-poohed the possibility of a direct interface between a brain and a machine—only in the late 1990s did scientists start learning enough about the brain and signal-processing to offer glimmers of hope that this science-fiction vision could become reality. Since then, insights into the workings of the brain—how it encodes commands for the body, and how it learns to improve those commands over time—have piled up at an astonishing pace, and the researchers at Duke studying the macaque and the robotic arm are at the leading edge of the technology. "This goes way beyond what's been done before," says neuroscientist Miguel Nicolelis, co-director of the Center for Neuroengineering. Indeed, the performance of the center's monkeys suggests that a mind-machine merger could become a reality in humans very soon.
    Nicolelis and his team are confident that in five years they will be able to build a robot arm that can be controlled by a person with electrodes implanted in his or her brain. Their chief focus is medical—they aim to give people with paralyzed limbs a new tool to make everyday life easier. But the success they and other groups of scientists are achieving has triggered broader excitement in both the public and private sectors. The Defense Advanced Research Projects Agency has already doled out $ 24 million to various brain-machine research efforts across the United States, the Duke group among them. High on DARPA's wish list. mind-controlled battle robots, and airplanes that can be flown with nothing more than thought. You were hoping for something a bit closer to home? How about a mental telephone that you could use simply by thinking about talking?
    Passage Two
    Within that exclusive group of literary characters who have survived through the centuries—from Hamlet to Huckleberry Finn  few can rival the cultural impact of Sherlock Holmes. Since his first public appearance 20 years ago, the gentleman with the curved pipe and a taste for cocaine, the master of deductive reasoning and elaborate disguise, has left his mark everywhere—in crime literature, film and television, cartoons and comic books.
    At Holmes' side, of course, was his trusted friend Dr. Watson. Looming even larger, however, was another doctor, one whose medical practice was so slow it allowed him plenty of time to pursue his literary ambition. His name: Arthur Conan Doyle. As the creator of these fictional icons, Conan Doyle has himself become something of a cult figure, the object of countless critical studies, biographies and fan clubs.
    Conan Doyle was born in Edinburgh in 1859, in a respectable middle-class Catholic family. Still, it was far from an easy life. There was never enough money; they moved frequently in search of lower rents; and his father, a civil servant and illustrator was an alcoholic who had to be institutionalized. Yet the early letters he wrote to his mother are surprisingly optimistic, concerned mainly with food, clothes, allowances and schoolwork. At 14 came his first unforgettable visit to London, including Madame Tussaud's, where he was "delighted with the room of Horrors, and the images of the murderers."
    A superb student, Conan Doyle went on to medical school, where he was attracted by Dr. Joseph Bell, a professor with an uncanny ability to diagnose patients even before they opened their mouths. For a time he worked as Bell's outpatient clerk and would watch, amazed, at how the location of a callus could reveal a man's profession, or how a quick look at a skin rash told Bell that the patient had once lived in Bermuda. In 1886, Conan Doyle outlined his first novel, A Study in Scarlet, which he described as "a simple tale of mystery to make a little extra money." Its main character, initially called Sherringford Hope and later called Sherlock Holmes, was based largely on Bell. But Holmes' first appearance went almost unnoticed, and the struggling doctor devoted nearly all of his spare time to writing long historical novels in the style of Sir Walter Scott—novels that he was convinced would make his reputation. It wasn't to be. In 1888, Holmes reappeared in A Scandal in Bohemia, a short story in Strand Magazine. And this time, its hero took an immediate hit and Conan Doyle's life would never be the same.
    Passage Three
    As many as one thousand years ago in the Southwest, the Hopi and Zuni Indians of North America were building with adobe—sun baked brick plastered with mud. Their homes looked remarkably like modern apartment houses. Some were four stories high and contained quarters for perhaps a thousand people, along with store rooms for grain and other goods. These buildings were usually put up against cliffs, both to make construction easier and for defense against enemies. They were really villages in themselves, as later Spanish explorers must have realized since they called them "pueblos", which is Spanish for town.
    The people of the pueblos raised what are called "the three sisters"—com, beans, and squash. They made excellent pottery and wove marvelous baskets, some so fine that they could hold water. The Southwest has always been a dry country, where water is scarce. The Hopi and Zuni brought water from streams to their fields and gardens through irrigation ditches. Water was so important that it played a major role in their religion. They developed elaborate ceremonies and religious rituals to bring rain.
    The way of life of less settled groups was simpler and more strongly influenced by nature. Small tribes such as the Shoshone and Ute wandered the dry and mountainous lands between the Rocky Mountains and the Pacific Ocean. They gathered seeds and hunted small animals such as small rabbits and snakes. In the Far North the ancestors of today's Inuit hunted seals, walruses, and the great whales. They lived right on the frozen seas in shelters called igloos built of blocks of packed snow. When summer came, they fished for salmon and hunted the lordly caribou.
    The Cheyenne, Pawnee, and Sioux tribes, known as the Plains Indians, lived on the grasslands between the Rocky Mountains and the Mississippi River. They hunted bison, commonly called the buffalo. Its meat was the chief food of these tribes, and its hide was used to make their clothing and covering of their tents and tipis.
    Passage Four
    Migration is usually defined as "permanent or semipermanent change of residence".
    "This broad definition, of course, would include a move across the street or a cross a city. Our concern is with movement between nations, not with internal migration within nations, although such movements often exceed international movements in volume. Today, the motives of people who move short distances are very similar to those of international migrants".
    Students of human migration speak of "push" and "pull" factors, which influence an individual's decision to move from one place to another. Push factors are associated with the place of origin. A push factor can be as simple and mild a matter as difficulty in finding a suitable job, or as traumatic as war, or severe famine. Obviously, refugees who leave their homes with guns pointed at their heads are motivated almost entirely by push factors (although pull factors do influence their choice of destination).
    Pull factors are those associated with the place of destination. Most of these are economic, such as better job opportunities or the availability of good land to farm. The latter was an important factor in attracting settlers to the United States during the 19th century. In general, pull factors add up to an apparently better chance for a good life and material well-being than is offered by the place of origin. When there is a choice between several attractive potential destinations, the deciding factor might be a non-economic consideration such as the presence of relatives, friends, or at least fellow countrymen already established in the new place who are willing to help the newcomers settle in. Considerations of this sort lead to the development of migration flow.
    Besides push and pull factors, there are what the sociologists call "intervening obstacles". Even if push and/or pull factors are very strong they still may be outweighed by intervening obstacles, such as the distance of the move, the trouble and cost of moving, the difficulty of entering the new country, and the problems likely to be encountered on arrival.
    The decision to move is also influenced by "personal factors" of the potential migrant. The same push/pull factors and obstacles operate differently on different people, sometimes because they are at different stages of their lives, or just because of their varying abilities and personalities. The prospect of packing up everything and moving to a new and perhaps very strange environment may app ear interesting and challenging to an unmarried young man and appallingly difficult to a slightly older man with a wife and small kids. Similarly, the need to learn a new language and customs may excite one person and frighten another.
    Regardless of why people move, migration of large numbers of people causes conflict. The United States and other western countries have experienced adjustment problems with each new wave of immigrants. The newest arrivals are usually given the lowest-paid jobs and are resented by native people who may have to compete with them for those jobs. It has usually taken several decades for each group to be accepted into the mainstream of society in the host country.1.  Why is it incredible for something happened in a lab at Duke University's Center?(Passage One)