单选题 Questions22-24 are based on the recording you have just heard.

单选题 Animals on the Move A. It looked like a scene from 'Jaws' but without the dramatic music. A huge shark was slowly swimming through the water, its tail swinging back and forth like the pendulum of a clock. Suddenly sensitive nerve ending in the shark's skin picked up vibrations of a struggling fish. The shark was immediately transformed into a deadly, efficient machine of death. With muscles taut, the shark knifed through the water at a rapid speed. In a flash the shark caught its victim, a large fish, in its powerful jaws. Then, jerking its head back and forth, the shark tore huge chunks of flesh from its victim and swallowed them. Soon the action was over. B. Moving to Survive In pursuing its prey, the shark demonstrated in a dramatic way the important role of movement, or locomotion, in animals. Like the shark, most animals use movement to find food. They also use locomotion to escape enemies, find a mate, and explore new territories. The methods of locomotion include crawling, hopping, slithering, flying, swimming, or walking. Humans have the added advantage of using their various inventions to move about in just about any kind of environment. Automobiles, rockets, and submarines transport humans from deep oceans to as far away as the moon. However, for other animals movement came about naturally through millions of years of evolution. One of the most successful examples of animal locomotion is that of the shark. Its ability to quickly zero in on its prey has always impressed scientists. But it took a detailed study by Duke University marine biologists S. A. Wainwright, F. Vosburgh, and J. H. Hebrank to find out how the sharks did it. In their study the scientists observed sharks swimming in a tank at Marine land in Saint Augustine, Fla. Movies were taken of the sharks' movements and analyzed. Studies were also made of shark skin and muscle. C. Skin Is the Key The biologists discovered that the skin of the shark is the key to the animal's high efficiency in swimming through the water. The skin contains many fibers that crisscross like the inside of a belted radial tire. The fibers are called collagen fibers. These fibers can either store or release large amounts of energy depending on whether the fibers are relaxed or taut. When the fibers are stretched, energy is stored in them the way energy is stored in the string of a bow when pulled tight. When the energy is released, the fibers become relaxed. D. The Duke University biologists have found that the greatest stretching occurs where the shark bends its body while swimming. During the body's back and forth motion, fibers along the outside part of the bending body stretch greatly. Much potential energy is stored in the fibers. This energy is released when the shark's body snaps back the other way. As energy is alternately stored and released on both sides of the animal's body, the tail whips strongly back and forth. This whip-like action propels the animal through the water like a living bullet. E. Source of Energy What causes the fibers to store so much energy? In finding the answer the Duke University scientists learned that the shark's similarity to a belted radial tire doesn't stop with the skin. Just as a radial tire is inflated by pressure, so, too, is the area just under the shark's collagen 'radials'. Instead of air pressure, however, the pressure in the shark may he due to the force of the blood pressing on the collagen fibers. F. When the shark swims slowly, the pressure on the fibers is relatively low, and the shark is able to bend its body at sharp angles. The animal swims this way when looking around for food or just swimming. However, when the shark detects an important food source, some fantastic involuntary changes take place. The pressure inside the animal may increase by 10 times. This pressure change greatly stretches the fibers, enabling much energy to be stored. This energy is then transferred to the tail, and the shark is off. The rest of the story is predictable. G. Dolphin Has Speed Record Another fast marine animal is the dolphin. This seagoing mammal has been clocked at speeds of 32 kilometers (20 miles) an hour. Biologists studying the dolphin have discovered that, like the shark, the animal's efficient locomotion can be traced to its skin. A dolphin's skin is made up in such a way that it offers very little resistance to the water flowing over it. Normally when a fish or other object moves slowly through the water, the water flows smoothly past the body. This smooth flow is known as laminar flow. However, at faster speeds the water becomes more turbulent along the moving fish. This turbulence muses friction and slows the fish down. H. In a dolphin the skin is so flexible that it bends and yields to the waviness of the water. The waves, in effect, become tucked into the skin's folds. This allows the rest of the water to move smoothly by in a laminar flow. Where other animals would be slowed by turbulent water at rapid speeds, the dolphin can race through the water at record breaking speeds. I. Other Animals Less Efficient Not all animals move as efficiently as sharks and dolphins. Perhaps the greatest loser in locomotion efficiency is the slug. The slug, which looks like a snail without a shell, lays down a slimy trail over which it crawls. It uses so much energy producing the slimy mucus and crawling over it that a mouse traveling the same distance uses only one twelfth as much energy. J. Scientists say that because of the slug's inefficient use of energy, its lifestyle must be restricted. That is, the animals are forced to confine themselves to small areas for obtaining food and finding proper living conditions. Have humans ever been faced with this kind of problem?

单选题 The unique human habit of taking in and employing animals—even competitors like wolves—spurred on human tool-making and language, which have both driven humanity's success, Pat Shipman says, paleoanthropologist of Penn State University. 'Wherever you go in the world, whatever ecosystem (生态系统), whatever culture, people live with animals, ' Shipman said. For early humans, taking in and caring for animals would seem like a poor strategy for survival. 'On the face of it, you are wasting your resources. So this is a very weird behavior, ' Shipman said. But it's not so weird in the context something else humans were doing about 2.6 million years ago: switching from a mostly vegetarian diet to one rich in meat. This happened because humans invented stone hunting tools that enabled them to compete with other top predators. Quite a rapid and bizarre switch for any animal. So we invented the equipment, learned how to track and kill, and eventually took in animals who also knew how to hunt—like wolves and other canines. Others, like goats, cows and horses, provided milk, hair and, finally, hides and meat. Managing all of these animals—or just tracking them—requires technology, knowledge and ways to preserve and convey information. So languages had to develop and evolve to meet the challenges. Tracking game has even been argued to be the origin of scientific inquiry, said Peter Richerson, professor emeritus (名誉退休的) in the Department of Environmental Science and Policy at the University of California, Davis. One of the signs that this happened is in petroglyphs (史前岩画) and other rock art left by ancient peoples. At first they were abstract, geometric patterns that are impossible to decipher (破译). Then they converge on one subject: animals. There have also been genetic changes in both humans and our animals. For the animals those changes developed because human bred them for specific traits, like a cow that gives more milk or a hen that lays more eggs. But this evolutionary influence works both ways. Dogs, for instance, might have been selectively taken in by humans who shared genes for more compassion. Those humans then prospered with the dogs' help in hunting and securing their homes.

单选题 最近，中国科学院(Chinese Academy of Sciences)出版了关于其最新科学发现与未来一年展望的年度系列报告。系列报告包括三部分：科学发展报告、高技术发展报告、中国可持续发展战略报告。第一份报告包含中国科学家的最新发现，诸如新粒子研究与H7N9病毒研究的突破。该报告还突出强调了未来几年需要关注的问题。第二份报告公布了一些应用科学研究的热门领域，如3D打印和人造器官研究。第三份报告呼吁加强顶层设计，以消除工业升级中的结构性障碍，并促进节能减排。

单选题 Questions2-5 are based on the conversation you have just heard.

单选题 围棋(go)于四千多年前起源于中国，是一种重要的棋盘游戏，并在一千多年前就先后传到朝鲜半岛(peninsula)和日本，为东北亚人们普遍喜爱。每年中、日、韩之间有多种围棋比赛，围棋成为文化交流的工具。围棋不仅是一个竞赛项目，也是一种游戏活动，文人(literati)的案台上常常备有围棋。客人来了，除了有酒，还有围棋。旧时，无论在农村还是在市井，人们常常可以见到这样的场面：两个人在对弈，旁边站着一大片观棋的人，观棋的人得到的快乐丝毫不比下棋的人少。

单选题 瑜伽有着六千多年的历史，起源于印度。古代的瑜伽信徒发展了瑜伽体系，他们深信通过运动身体和调控呼吸完全可以控制心智和情感(control one's mind and emotions)，保持身体长久的健康。瑜伽姿势大部分来源于模仿动物的姿态，达到锻炼身心的效果。瑜伽不同于体操和舞蹈，也不同于一般的有氧练习。只有当呼吸、意识和姿势结合成一体(breathing, mind and posture get into one)时，才是真正的瑜伽练习。可以说，瑜伽不仅仅是一种运动方式，也是一种生活态度。

单选题 It's possible to admire Oprah Winfrey and still wish Harvard hadn't awarded her an honorary doctor of law degree and the commencement (毕业典礼)speaker spot at yesterday's graduation. There's no question Oprah's achievements place her in the temple of American success stories. Talent, charm, and an exceptional work ethic have rarely hurled anyone as far as they have this former abused teenage mother from rural Mississippi who became one of the world's most successful entertainment icons and the first African-American female billionaire. Honorary degrees are often conferred on non-academic leaders in the arts, business, and politics. Harvard's list in recent years has included Kofi Annan, Bill Gates, Meryl Streep, and David Souter. But Oprah's particular brand of celebrity is not a good fit for the values of a university whose motto (座右铭), Veritas, means truth. Oprah's passionate advocacy extends, unfortunately, to a hearty embrace of fake science. Most notoriously, Oprah's validation of Jenny McCarthy's claim that vaccines cause autism (自闭症) has no doubt contributed to much harm through the foolish avoidance of vaccines. Famous people are entitled to a few failings like the rest of us, and the choice of commencement speakers often reflects a balance of institutional priorities and aspirations. Judging from our conversations with many students, Oprah was a widely popular choice. But this vote of confidence in Oprah sends a troubling message at precisely the time when American universities need to do more to advance the cause of reason. As former Dean of Harvard College, Harry Lewis, noted in a blog post about his objections, 'It seems very odd for Harvard to honor such a high profile popularizer of the irrational... at a time when political and religious nonsense so jeopardize the rule of reason in this allegedly enlightened democracy and around the world.' As America's oldest and most visible university, Harvard has a special opportunity to convey its respect for science not only through its research and teaching programs but also in its public affirmation of evidence-based inquiry. Unfortunately, many American universities seem awfully busy protecting their brand name and not nearly busy enough protecting the pursuit of knowledge. A recent article in The Harvard Crimson noted the shocking growth of Harvard's public relations arm in the last five years and it questioned whether a focus on risk management and avoiding controversy was really the best outward-looking face of this great institution. As American research universities begin to resemble profit centers and entertainment complexes, it's easy to lose sight of their primary mission: to produce and spread knowledge. This mission depends on traditions of rational discourse and vigorous defense of the scientific method. Oprah Winfrey's honorary doctorate was a step in the wrong direction.

单选题Directions:Forthispart,youareallowed30minutestowriteanessaybasedonthefollowingdrawing.Inyouressay,youshouldfirstdescribethedrawingandinterpretitsmeanings,andthengiveyourcommentonit.Youarerequiredtowriteatleast150wordsbutnomorethan200words.

单选题 The United States has a major problem on its hands. Tree, Britain is facing a similar problem, but for the time being it is in America that it is graver. The only way to solve it is through education. Negroes (黑人) should know about the contributions that black individuals and groups have made towards building America. This is of vital importance for their self-respect: and it is perhaps even more important for white people to know. For if you believe that a man has no history worth mentioning, it is easy to assume that he has no value as a man. Many people believe that, since the Negro’s achievements do not appear in the history books, he did not have any. Most people are taken aback when they learn that Negroes sailed with Columbus, marched with the Spanish conquerors of South America and fought side by side with white Americans in all their wars. People are astonished when you tell them about Phillis Wheatley, who learned English as a salve in Boston and wrote first-class poetry. They have never heard of Benjamin Banneker, a mathematician and a surveyor, who helped to plan the city of Washington. There has been a tendency all along to treat the black man as if he were invisible. Little has been written about the 5, 000 American Negroes who fought in the Revolution against the British, but they were in every important battle. In the Anglo-American War of 1812, at least one out of every six men in the U. S. Navy was a Negro. In the Civil War, more than 200, 000 black troops fought in the Union forces. How, then, did the image of the Negro as a valiant fighting man disappear? To justify the hideous institution of slavery, slave-holders had to create the myth of the docile, slow-witted Negro. incapable of self-improvement, and even contented with his lot. Nothing could be further from the truth. The slave fought for his freedom at every chance he got, and there were numerous uprisings. Yet the myth of docility persisted. There are several other areas where the truth has been twisted or concealed. Most people have heard of the Negro, Carver, who invented scores of new uses for the lowly peanut. But whoever heard of Norbert Rillieux, who in 1846 invented a vacuum pan that revolutionized the sugar-refining industry? Or of Elijah McCoy, who in 1872invented the drip cup that feeds oil to the moving parts of heavy machinery? How many people know that Negroes are credited with inventing such different items as ice creams, potato chips, the gas mask and the first traffic light? Not many. As for the winning of the West, the black cowboy and the black frontiersman have been almost ignored, though film producers are becoming more aware of their importance. Yet in the typical trail crew of eight men that drove cattle from Texas to Kansas, at least two would have been Negroes. The black troops of the Ninth and Tenth Cavalry formed one-fifth of all the mounted troops assigned to protect the frontier after the Civil War. 'What difference does it make?' you may ask. A lot. The cowboy is the American folk-hero. Youngsters identify with him instantly. The average cowboy film is really a kind of morality play, with good guys and bad guys and right finally triumphing over wrong. You should see the amazement and happiness on black youngsters’ faces when they learn that their ancestors really had a part in all that.

单选题 Questions2-4 are based on the conversation you have just heard.

单选题 Data sharing: An open mind on open data A. It is a movement building steady momentum: a call to make research data, software code and experimental methods publicly available and transparent. A spirit of openness is gaining acceptance in the science community, and is the only way, say advocates, to address a 'crisis' in science whereby too few findings are successfully reproduced. Furthermore, they say, it is the best way for researchers to gather the range of observations that are necessary to speed up discoveries or to identify large-scale trends. B. The open-data shift poses a confusing problem for junior researchers. On the one hand, the drive to share is gathering official steam. Since 2013, global scientific bodies have begun to back policies that support increased public access to research. On the other hand, scientists disagree about how much and when they should share data, and they debate whether sharing it is more likely to accelerate science and make it more robust, or to introduce vulnerabilities and problems. As more journals and funders adopt data-sharing requirements, and as a growing number of enthusiasts call for more openness, junior researchers must find their place between adopters and those who continue to hold out, even as they strive to launch their own careers. C. One key challenge facing young scientists is how to be open without becoming scientifically vulnerable. They must determine the risk of jeopardizing a job offer or a collaboration proposal from those who are wary of—or unfamiliar with—open science. And they must learn how to capitalize on the movement's benefits, such as opportunities for more citations and a way to build a reputation without the need for conventional metrics, such as publication in high-impact journals. D. Some fields have embraced open data more than others. Researchers in psychology, a field rocked by findings of irreproducibility in the past few years, have been especially vocal supporters of the drive for more-open science. A few psychology journals have created incentives to increase interest in reproducible science—for example, by affixing an 'open-data' badge to articles that clearly state where data are available. According to social psychologist Brian Nosek, executive director of the Center for Open Science, the average data-sharing rate for the journal Psychological Science, which uses the badges, increased tenfold to 38% from 2013 to 2015. E. Funders, too, are increasingly adopting an open-data policy. Several strongly encourage, and some require, a date-management plan that makes data available. The US National Science Foundation is among these. Some philanthropic (慈善的) funders, including the Bill Melinda Gates Foundation in Seattle, Washington, and the Wellcome Trust in London, also mandate open data from their grant recipients. F. But many young researchers, especially those who have not been mentored in open science, are uncertain about whether to share or to stay private. Graduate students and postdoes, who often are working on their lab head's grant, may have no choice if their supervisor or another senior colleague opposes sharing. G. Some fear that the potential impact of sharing is too high, especially at the early stages of a career. 'Everybody has a scary story about someone getting scooped (被抢先),' says New York University astronomer David Hogg. Those fears may be a factor in a lingering hesitation to share data even when publishing in journals that mandate it. H. Researchers at small labs or at institutions focused on teaching arguably have the most to lose when sharing hard-won data. 'With my institution and teaching load, I don't have postdocs and grad students,' says Terry McGlynn, a tropical biologist at California State University, Dominguez Hills. 'The stakes are higher for me to share data because it's a bigger fraction of what's happening in my lab.' I. Researchers also point to the time sink that is involved in preparing data for others to view. Once the data and associated materials appear in a repository (存储库), answering questions and handling complaints can take many hours. J. The time investment can present other problems. In some cases, says data scientist Karthik Ram, it may be difficult for junior researchers to embrace openness when senior colleagues—many of whom head selection and promotion committees—might ridicule what they may view as misplaced energies. 'I've heard this recently—that embracing the idea of open data and code makes traditional academics uncomfortable,' says Ram. 'The concern seems to be that open advocates don't spend their time being as productive as possible.' K. An open-science stance can also add complexity to a collaboration. Kate Ratliff, who studies social attitudes at the University of Florida, Gainesville, says that it can seem as if there are two camps in a field—those who care about open science and those who don't. 'There's a new area to navigate—'Are you cool with the fact that I'll want to make the data open?'—when talking with somebody about an interesting research idea,' she says. L. Despite complications and concerns, the upsides of sharing can be significant. For example, when information is uploaded to a repository, a digital object identifier (DOI) is assigned. Scientists can use a DOI to publish each step of the research life cycle, not just the final paper. In so doing, they can potentially get three citations—-one each for the data and software, in addition to the paper itself. And although some say that citations for software or data have little currency in academia, they can have other benefits. M. Many advocates think that transparent data procedures with a date and time stamp will protect scientists from being scooped. 'This is the sweet spot between sharing and getting credit for it, while discouraging plagiarism (剽窃),' says Ivo Grigorov, a project coordinator at the National Institute of Aquatic Resources Research Secretariat in Charlottenlund, Denmark. Hogg says that scooping is less of a problem than many think. 'The two cases I'm familiar with didn't involve open data or code,' he says. N. Open science also offers junior researchers the chance to level the playing field by gaining better access to crucial data. Ross Mounce, a postdoc studying evolutionary biology at the University of Cambridge, UK, is a vocal champion of open science, partly because his fossil-based research depends on access to others' data. He says that more openness in science could help to discourage what some perceive as a common practice of shutting out early-career scientists' requests for data. O. Communication also helps for those who won-y about jeopardizing a collaboration, he says. Concerns about open science should be discussed at the outset of a study. 'Whenever you start a project with someone, you have to establish a clear understanding of expectations for who owns the data, at what point they go public and who can do what with them,' he says. P. In the end, sharing data, software and materials with colleagues can help an early-career researcher to gain recognition—a crucial component of success. 'The thing you are searching for is reputation,' says Titus Brown, a genomics (基因组学) researcher at the University of California, Davis. 'To get grants and jobs, you have to be relevant and achieve some level of public recognition. Anything you do that advances your presence—-especially in a larger sphere, outside the communities you know—is a net win.'

单选题 话题：要勇于面对挑战We should face challenges bravely Directions: For this part, you are allowed 30 minutes to write an essay on facing challenges by referring to the saying 'You cannot change what you refuse to confront.' You can give examples to illustrate your point and then explain how you will react to challenges in your life. You should write at least 150 words but no more than 200 words.