填空题[A]Itisalsousedtohelpstudentsgaintransitionskills:Studentswithautismordevelopmentaldelaycanvisitavirtualsupermarket,takepublictransportation,crossthestreet,ororganizehisorherday.Studentsinwheelchairscanlearnhowtonavigatebuildings.Andthebeautyis,thesestudentscanmakeanynumberofmistakeswithoutendangeringthemselves.[B]Forexample,virtualrealityhasbeenusedeffectivelytoassessstudents'depthperception,withtheresultsbeingquitedifferentfromthoseobtainedfromtraditionalpaperandpenciltests.[C]Thenwegraduallybeginshrinkingthesignandaddingotherenvironmentalelements.Oncethestudenthasmasteredthisvirtually,heorshetransferstheknowledgetotherealworld.Intheend,thisisthemostimportantfunctionofvirtualrealityprogramsforspecialstudents.[D]Virtualrealityevenallowsustotailortheworldtomeetachild'sneeds.Let'ssaywe'reteachingachildtocrossthestreetbypayingattentiontotrafficsigns.Educatorshavefoundthatitisoftendifficultforthechildtolocatethetrafficsigninabusyenvironment.Withvirtualreality,wecanblowupthe"walksign"sothestudentknowswhatitlookslike.[E]Anditisexpectedthatfutureteacherswillbeexposedtovirtualclasses,completewith"difficultstudents"tohelpthemmasterbehaviormanagementtechniques.[F]Infact,oneofthebiggestvirtuesofvirtualrealityisthatitallowsstudentstolearninasafeenvironment,andthisholdstrueforstudentswithbehaviordisorders.Afterastudenthaslearnedanappropriatebehaviororwayofcontrollinghisorheranger,thestudentisputinprogressivelymoredifficultvirtualsocialsituationswhereheorshecanpracticethenewtechnique.[G]Someoftoday'smostcutting-edgetechnologyisnowbeingusedtohelpstudentswithspecialneeds.Nolongerjusttheprovinceofgamesfor"videoneeds,"virtualrealityhascomeintoitsownasatoolforspecialeducationteachersandtherapists.Assuch,itisusedforassessment,teaching,andpractice,accordingtoSkipRizzo,researchassistant/professorattheUniversityofSouthernCalifornia.

填空题[A] What route does HIV take after it enters the body to destroy the immune system?[B] How and when did the long-standing belief concerning AIDS and HIV crop up?[C] What is the most effective anti-HIV therapy?[D] How does HIV subvert the immune system?[E] In the absence of a vaccine, how can HIV be stopped?[F] Why does AIDS predispose infected persons to certain types of cancer and infections? In the 20 years since the first cases of AIDS were detected, scientists say they have learned more about this viral disease than any other. Yet Peter Piot, who directs the United Nations AIDS program, and Stefano Vella of Rome, president of the International AIDS Society, and other experts say reviewing unanswered questions could prove useful as a measure of progress for AIDS and other diseases. Among the important broader scientific questions that remain:41．_____________. A long-standing belief is that cancer cells constantly develop and are held in check by a healthy immune system. But AIDS has challenged that belief. People with AIDS are much more prone to certain cancers like non-Hodgkins lymphomas and Kaposi's sarcoms, but not to breast, colon and lung, the most common cancers in the United States. This pattern suggests that an impaired immune system, at least the type that occurs in AIDS, does not allow common cancers to develop.42．_______________. When HIV is transmitted sexually, the virus must cross a tissue barrier to enter the body. How that happens is still unclear. The virus might invade directly or be carried by a series of different kinds of cells. Eventually HIV travels through lymph vessels to lymph nodes and the rest of the lymph system. But what is not known is how the virus proceeds to destroy the body's CD-4 cells that are needed to combat invading infectious agents.43．_______________. Although HIV kills the immune ceils sent to kill the virus, there is widespread variation in the rate at which HIV infected people become ill with AIDS. So scientists ask: Can the elements of the immune system responsible for that variability be identified? If so, can they be used to stop progression to AIDS in infected individuals and possibly prevent infection in the first place?44．_______________. In theory, early treatment should offer the best chance of preserving immune function. But the new drugs do not completely eliminate HIV from the body so the medicines, which can have dangerous side effects, will have to be taken for a lifetime and perhaps changed to combat resistance. The new policy is expected to recommend that treatment be deferred until there are signs the immune system is weakening. Is a vaccine possible? There is little question that an effective vaccine is crucial to controlling the epidemic. Yet only one has reached the stage of full testing, and there is wide controversy over the degree of protection it will provide. HIV strains that are transmitted in various areas of the world differ genetically. It is not known whether a vaccine derived from one type of HIV will confer protection against other types.45．_______________. Without more incisive, focused behavioral research, prevention messages alone will not put an end to the global epidemic.

填空题The renewable-fuel standard released in February by America's Environmental Protection Agency (EPA) paints an ambitious picture of biofuels' future. It wants the amount of the stuff used as transport fuel to climb from 13 billion gallons (49 billion litres) in 2010 to 36 billion gallons in 2022, requiring by far the largest part of that increase to come from various advanced biofuels, rather than ethanol made from corn (maize). But although the future looks exciting, the present is rather grim. (41) The fact that corn-ethanol production has continued to grow, despite the failure of a number of finns in late 2008 and early 2009, points to the efficacy of the various protections and subsidies it enjoys (falling maize prices helped too), though it says nothing about their efficiency or wisdom. Ethanol, which is used mainly as an additive to petrol, is not a particularly good fuel: it offers only about two- thirds as much energy as petrol and can corrode pipelines and car engines. (42) Even as producers have urged the EPA to lift this bar, it has challenged them to move beyond corn and make ethanol from cellulose, the abundant, inedible portion of most crops. Using inedible inputs avoids fights about diverting food crops for fuel, and frees the industry from reliance on a single commodity. Despite ample investment, however, production costs remain high and commercialisation elusive. (43) Still, it and others are gamely pushing ahead. A boost came last month, when Novozymes and Danisco, two Danish firms, unveiled new, cheaper enzymes which are needed to break down cellulose. (44) The alternative is to produce something better, such as an advanced biodiesel. According to Lux Research, based in Boston, venture capitalists invested $208m in algae technologies with this sort of thing in mind during 2008, six times as much as they spent in 2007. But building vast pools for algae and turning them into fuel remains tremendously expensive. Solazyme, a Californian firm, is a promising anomaly, using algae to make fuel from sugars in dark industrial vats rather than pools. Such strategies may work, but have yet to be scaled up. Solazyme, tellingly, has developed other sources of revenue. America's government is doling out grants and loan guarantees, and oil companies are investing, too. Solazyme has a partnership with Chevron. Valero, America's biggest oil refiner, has bought up troubled ethanol plants and invested in firms that use plant material, algae and rubbish to produce fuel. (45) "It still feels like the final bets have not been made ," explains Phil New, the head of BP Biofuels. A. By 2014 or earlier, ethanol production is expected to reach 10% of America's total fuel demand, and thus to hit a "blend wall", since the EPA does not at present allow blends of more than 10% for mainstream use. B. Since 2007 one company, Range Fuels, has received more than $150m in federal grants and guarantees for a large cellulosic-ethanol plant, but has yet to produce any. C. The EPA has been forced to slash its 2010 mandate for the most widely touted of the non-corn biofuels, cellulosic ethanol, from 100m gallons to just 6.5m, less than a thousandth of the 11 billion gallons produced from corn in 2009. D. Algaz technologies had already become the available advanced biofuels which could lower the cost. E. Even if cellulosic ethanol were to get cheaper, though, it would still be ethanol, a poor fuel. F. Advanced biofuel have the government's subsidy and loan guarantees. G. BP's broad-based portfolio includes investments in Brazilian sugarcane ethanol, cellulosic ethanol and a partnership with DuPont to produce biobutanol.

填空题The human nose is an underrated tool

填空题Directions: In the following article, some sentences have been removed. For Questions 41- 45, choose the most suitable one from the list A-G to fit into each of the numbered blank. There are two extra choices, which do not fit in any of the gaps. Mark your answers on ANSWER SHEET 1. (10 points) You don't have to convince Steve Backley of the power of the mind over the body. When the British javelin thrower, who won bronze in Barcelona in 1992 and silver in Atlanta in 1996, was unable to walk (let alone train ) after spraining his ankle a few years ago, he worked out in a "mental gym". Sitting in a chair, he imagined himself throwing the javelin in every one of the world's major track-and-field stadiums, until he had racked up about a thousand hurls. 41.______ Whether it is golfer Earl Woods teaching his son Tiger to form a mental image of the ball's rolling into the hole, or Olympic weight-lifter Tara Nott's training her brain to block out distractions, a strong mental game has always been part of elite sports. Michael Jordan, Nancy Kerrigan and Jack Nicklaus all practiced their moves mentally; Jean-Claude Killy used to ski a slalom course in his head many times before exploding out of the starting gate. "Everybody is pretty much at the same level physically," says American diver Michelle Davison, "[ The difference comes down to] who can hold it together mentally. " 42. ______ While coaches and trainers have long emphasized the importance of the mental game, exactly how the mind affects the body's performance has always been a bit of a mystery, with buzzwords like "in the zone" and "mental imagery" carrying a vague whiff of quackery. 43. ______ "Mental practice can actually increase real-world strength and performance," says neuroscientist Ian Robertson of Trinity College Dublin, who describes the power of mental workouts in his engaging new book, Mind Sculpture. "Pumping virtual iron physically changes the brain—and the brain, after all, controls the body. " 44. ______ Imagine, in your mind's eye, a harp in all its graceful detail; the same region of your visual cortex just turned on as if you actually looked at the instrument. But what matters to athletes is that, just as visual imagery activates the brain's visual cortex, so imagining movement activates the motor cortex, notes Harvard University's Stephen Kosslyn, who has done pioneering research on imagery. Imagine tensing and relaxing the muscles of your right index finger, but without actually moving. Were you to do this for several minutes every day for four weeks, at the end of the period the strength of that finger would increase by 20% or so, as researchers found in 1992 when they had volunteers follow this mental regimen. Nothing changed in the finger muscles themselves as a result of the imagery. 45. ______ That's probably why imaging is such a powerful, and popular, mental workout for athletes.[A] The reason is that visualization activates many of the same neural circuits that actually seeing does.[B] The same process likely occurred in Backley's brain as he mentally hurled the javelin. "Through mental practice, [he] kept stimulating the networks of connected neurons where his skill was embroidered," Robertson writes.[C] He returned to competition a few weeks later making his top distances; usually, losing weeks of throwing practice will set you back inches—and in sports of course, inches might as well be miles.[D] Instead connections between nerves and the muscles they control, in a circuit starting in the motor cortex of the brain, got stronger. "The improvements in strength were caused by changes in the brain," says Robertson.[E] But just as physicians are showing that something as inchoate as a positive outlook can affect something as real as the progress of breast cancer, so scientists are uncovering how mental imagery and other tricks of the athlete's trade affect the real, physical brain and hence the body.[F] That lesson has not been lost on the U. S. Olympic Committee. It had one full-time sports psychologist in 1988. Today it has five.[G] A 1995 study in Boston compared the brain regions of people who physically practiced a five- finger piano exercise with people who mentally practiced it. In both groups the area of the brain devoted to moving the fingers got bigger and accuracy improved.

填空题{{B}}Directions:{{/B}}In the following text, some sentences have been removed. Choose the most suitable one from the list A-G to fit into each of the numbered blanks. There are two extra choices, which do not fit in any of the blanks. Mark your answers on the ANSWER SHEET. Would you be happier if you spent more time discussing the state of the world and the meaning of life-and less time talking about the weather? {{U}} 1 {{/U}}______. "We found this so interesting, because it could have gone the other way-it could have been, 'Don't worry, be happy'—as long as you surf on the shallow level of life you're happy, and if you go into the existential depths you'll be unhappy," Dr. Mehl said. {{U}} 2 {{/U}}______. "By engaging in meaningful conversations, we manage to impose meaning on an otherwise pretty chaotic world, " Dr. Mehl said. "And interpersonally, as you find this meaning, you bond with your interactive partner, and we know that interpersonal connection and integration is a core fundamental foundation of happiness." Dr. Mehl's study was small and doesn't prove a cause-and-effect relationship between the kind of conversations one has and one's happiness. {{U}} 3 {{/U}}______. The study, published in the journal Psychological Science, involved 79 college students-32 men and 47 women-who agreed to wear an electronically activated recorder with a microphone on their lapel that recorded 30-second snippets of conversation every 12.5 minutes for four days, creating what Dr. Mehl called "an audio diary of their day." {{U}} 4 {{/U}}______. A conversation about a TV show wasn't always considered small talk; it could be categorized as substantive if the speakers analyzed the characters and their motivations, for example. Many conversations were more practical and did not fit in either category, including questions about homework or who was taking out the trash, for example, Dr. Mehl said. Over all, about a third of all conversation was ranked as substantive, and about a fifth consisted of small talk. But the happiest person in the study, based on self-reports about satisfaction with life and other happiness measures as well as reports from people who knew the subject, had twice as many substantive conversations, and only one-third of the amount of small talk as the unhappiest, Dr. Mehl said. Almost every other conversation the happiest person had-45.9 percent of the day's conversations— were substantive, while only 21.8 percent of the unhappiest person's conversations were substantive. {{U}} 5 {{/U}}______. Next, Dr. Mehl wants to see if people can actually make themselves happier by having more substantive conversations. "It's not that easy, like taking a pill once a day," Dr. Mehl said. "But this has always intrigued me. Can we make people happier by asking them, for the next five days, to have one extra substantive conversation every day?" A. It may sound unreasonable, but people who spend more of their day having deep discussions and less time engaging in small talk seem to be happier, said Matthias Mehl, a psychologist at the University of Arizona. B. Just try having a substantive conversation in a group of moms...absolutely impossible. No matter what topic you start off with, the subject of the discussion invariably moves back to their kids. C. People who feel the most intensely will likely fall into the more extreme categories such as very happy or very sad, and the questionnaire likely attracted participants who were more in the "very happy" phase of their life because the very sad people are non-participants. D. Researchers then went through the tapes and classified the conversations as either small talk about the weather or having watched a TV show, and more substantive talk about current affairs, philosophy, the difference between Baptists and Catholics or the role of education. E. But, he proposed, substantive conversation seemed to hold the key to happiness for two main reasons. both because human beings are driven to find and create meaning in their lives, and because we are social animals who want and need to connect with other people. F. But that's the planned next step, when he will ask people to increase the number of substantive conversations they have each day and cut back on small talk, and vice versa. G. Small talk made up only 10 percent of the happiest person's conversations, while it made up almost three times as much-or 28.3 percent-of the unhappiest person's conversations.

填空题Most people would not object to living a few years longer than normal, as long as it meant they could live those years in good health. Sadly, the only proven way to extend the lifespan of an animal in this way is to reduce its calorie intake. Studies going back to the 1930s have shown that a considerable reduction in consumption (about 50%) can extend the lifespan of everything from dogs to nematode worms by between 30% and 70%. Although humans are neither dogs nor worms, a few people are willing to give the calorie-restricted diet a try in the hope that it might work for them, too. But not many—as the old joke has it, give up the things you enjoy and you may not live longer, but it will sure seem as if you did. Now, though, work done by Marc Hellerstein and his colleagues at the University of California, Berkeley, suggests that it may be possible to have, as it were, your cake and eat it too. Or, at least, to eat 95% of it. Their study, to be published in the American Journal of Physiology—Endocrinology and Metabolism, suggests that significant gains in longevity might be made by a mere 5% reduction in calorie intake. The study was done on mice rather than people. But the ubiquity of previous calorie-restriction results suggests the same outcome might well occur in other species, possibly including humans. However, you would have to fast on alternate days. (41)__________ Cancer is the uncontrolled growth of cells. For a cancer to develop efficiently, it needs multiple mutations to accumulate in the DNA of the cell that becomes the tumor's ancestor. (42)__________ A slower rate of cell division thus results in a slower accumulation of cancer-causing mutations. (43)__________ Heavy water is heavy because the hydrogen in it weighs twice as much as ordinary hydrogen(it has a proton and a neutron in its nucleus, instead of just a proton). Chemically, however, it behaves like its lighter relative. This means, among other things, that it gets incorporated into DNA as that molecule doubles in quantity during cell division. (44)__________ Dr Hellerstein first established how much mice eat if allowed to feed as much as they want. Then he set up a group of mice that were allowed to eat only 95% of that amount. In both cases, he used the heavy-water method to monitor cell division. The upshot was that the rate of division in the calorie-restricted mice was 37% lower than that in those mice that could eat as much as they wanted—which could have a significant effect on the accumulation of cancer-causing mutations. (45)__________[A] To stop this happening, cells have DNA-repair mechanisms. But if a cell divides before the damage is repaired, the chance of a successful repair is significantly reduced.[B] Bingeing and starving is how many animals tend to feed in the wild. The uncertain food supply means they regularly go through cycles of too much and too little food (it also means that they are often restricted to eating less than they could manage if food were omnipresent).[C] But calorie-reduction is not all the mice had to endure. They were, in addition, fed only on alternate days: bingeing one day and starving the next. So, whether modern man and woman, constantly surrounded by food and advertisements for food, would really be able to forgo eating every other day is debatable.[D] Why caloric restriction extends the lifespan of any animal is unclear, but much of the smart money backs the idea that it slows down cell division by denying cells the resources they need to grow and proliferate. One consequence of that slow-down would be to hamper the development of cancerous tumors.[E] So, by putting heavy water in the diets of their mice, the researchers were able to measure how much DNA in the tissues of those animals had been made since the start of the experiment (and by inference how much cell division had taken place), by the simple expedient of extracting the DNA and weighing it.[F] The second reason, according to Elaine Hsieh, one of Dr Hellerstein's colleagues, is that cutting just a few calories overall, but feeding intermittently, may be a more feasible eating pattern for some people to maintain than making small reductions each and every day.[G] At least, that is the theory. Until now, though, no one has tested whether reduced calorie intake actually does result in slower cell division. Dr Hellerstein and his team were able to do so using heavy water as a chemical "marker" of the process.

填空题It comes as a surprise, given Microsoft's notorious tenacity, but the software giant is definitely out to clear its antitrust plate. After its settlement with the Justice Department, the company has now struck an agreement to end more than 100 private class-action suits and signalled that it wants to do the same for the case brought against it by the European Commission. (41) Yet recent events suggest that it will not be that easy for Microsoft to shrug off its legal woes. For a start, the nine state attorneys-general opposing the federal settlement have asked the trial judge to Impose tougher remedies. (42) . And this week, a Senate committee hearing was dominated by criticism of the federal settlement. The least of Microsoft's problems are the class-action suits, filed on behalf of consumers who say they were harmed by the company's behaviour. Giving money to schools is a good idea. But half of the gift would be in the form of free Microsoft software, costing the company almost nothing, and hurting competitors in the education market, mainly Apple. So worried is Steve Jobs, Apple's boss, that he has publicly criticised the deal—after haying kept quiet during the entire antitrust trial. (43) The proposal of the dissenting states is more serious. (44) . Central to the plan are remedies concerning Microsoft's browser software and the Java programming language: the company would be forced to license the source code m its browser, and to make sure that Java programs can run on Windows. Microsoft would also be required m offer a stripped-down version of Windows so that PC makers could choose add-ons other than its own. Microsoft says that the proposed remedies are "extreme and not commensurate with what is left of the case". Colleen Kollar-Kotelly, the trial judge, will decide next spring. She has put the case on two parallel tracks. One is a review of the existing Justice Department settlement (under the Tunney act) to determine if it is in the public interest. The other is litigation over the newly proposed remedies. The European Commission. for its part, will probably wait and see what transpires m America before proceeding. It is unlikely simply to rubber-stamp the outcome as Microsoft has suggested. For one thing, European regulators have disagreements of their own with the company, chiefly that it is trying to extend its monopoly into the server and media-player markets. But competitors and critics of the software giant, who have heavily lobbied both the states and Brussels, should not get their hopes up. Given the economic and political environment, it is still unlikely that Microsoft will get more than a slap on the wrist, even if it hurts more than the company would like. (45) To some extent this is already happening. The "Liberty Alliance", for example, is gaining momentum. American Express and AOL Time Warner recently joined this coalition, whose goal is to provide an alternative to Microsoft's online authentication service, called Passport. Similarly, if the entertainment industry got its act together, it might be able to stop Microsoft defining the standard for digital copy-protection. Perhaps this time around, such alliances will prove a better match for Microsoft's determination.[A] Businesses and consumers want benefits of being connected anytime, anyplace—without compromising security or control of personal information.[B] Its rivals would perhaps do better to concentrate their energies on forming alliances that could help to keep Microsoft in check.[C] About 12,500 schools—many of which are among the nation's poorest—would be eligible to receive software from Microsoft under the proposal.[D] Another judge supervising the class-action suits has questioned Microsoft's plan to settle all of the eases by donating $1 billion to poor schools.[E] As if to underline this new approach, Microsoft recently announced that William Neukom, its long-serving general counsel, will soon be replaced by Brad Smith, his more convivial deputy,[F] Their suggested remedies do more than just plug the loopholes in the main settlement and provide for tougher enforcement. They would take back much of what Microsoft has won by abusing its monopoly power.[G] The judge's remarks suggest that Microsoft will have to pay cash in full if it wants him m approve the agreement.

填空题 [A] Human history contains great stories that can help us appreciate more about past life.[B] The great achievement can provide motivation for learners.[C] Making us more human, more than anything else, is the purpose of studying history.[D] Learning history can lead a more colorful life.[E] History can tell us when we should give up.[F] History can teach us a lesson from its mistakes. The speaker alleges that studying history is valuable only insofar as it is relevant to our daily lives. I find this allegation to be specious. It wrongly suggests that history is not otherwise instructive and that its relevance to our everyday lives is limited. To the contrary, studying history provides inspiration, innumerable lessons for living, and useful valueclarification and perspective—all of which help us decide how to live our lives. 41.______ To begin with, learning about great human achievements of the past provides inspiration. For example, a student inspired by the courage and tenacity of history's great explorers might decide as a result to pursue a career in archeology, oceanography, or astronomy. This decision can, in turn, profoundly affect that student's everyday life—in school and beyond. Even for students not inclined to pursue these sorts of careers, studying historical examples of courage in the face of adversity can provide motivation to face their own personal fears in life. In short, learning about grand accomplishments of the past can help us get through the everyday business of living, whatever that business might be, by emboldening us and lifting our spirits. 42.______ In addition, mistakes of the past can teach us as a society how to avoid repeating those mistakes. For example, history can teach us the inappropriateness of addressing certain social issues, particularly moral ones, on a societal level. Attempts to legislate morality invariably fail, as aptly illustrated by the Prohibition experiment in the U.S. during the 1930s. Hopefully, as a society we can apply this lesson by adopting a more enlightened legislative approach toward such issues as free speech, criminalization of drug use, criminal justice, and equal rights under the law. 43.______ Studying human history can also help us understand and appreciate the mores, values, and ideals of past cultures. A heightened awareness of cultural evolution, in turn, helps us formulate informed and reflective values and ideals for ourselves. Based on these values and ideals, students can determine their authentic life path as well as how they should allot their time and interact with others on a day-to-day basis. 44.______ Finally, it might be tempting to imply from the speaker's allegation that studying history has little relevance even for the mundane chores that occupy so much of our time each day, and therefore is of little value. However, from history we learn not to take everyday activities and things for granted. By understanding the history of money and banking we can transform an otherwise routine trip to the bank into an enlightened experience, or a visit to the grocery store into an homage to the many inventors, scientists, engineers, and entrepreneurs of the past who have made such convenience possible today. And, we can fully appreciate our freedom to go about our daffy lives largely as we choose only by understanding our political heritage. In short, appreciating history can serve to elevate our everyday chores to richer, more interesting, and more enjoyable experiences. 45.______ In sum, the speaker fails to recognize that in all our activities and decisions--from our grandest to our most rote--history can inspire, inform, guide, and nurture. In the final analysis, to study history is to gain the capacity to be more human--and I would be hard- pressed to imagine a worthier end.