专业八级分类模拟187及答案解析.doc

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1、专业八级分类模拟 187 及答案解析(总分：100.10，做题时间：90 分钟)一、READING COMPREHENSIO(总题数：1，分数：100.00)Section A Multiple-Choice Questions In this section there are several passages by fourteen multiple choice questions. For each multiple choice qutestion, there are four suggested answers marked A. B, C and D. Choose the o

2、ne that you think is the best answer and mark your answers on ANSWER SHEET TWO. PASSAGE ONE Countless medical studies have concluded that playing too many video games can be harmful to one“s health. Now, however, it turns out that One of the more popular video-game consoles on the market, the Xbox 3

3、60, could be used to save lives. A computer scientist at the University of Warwick in England has devised a way to use an Xbox 360 to detect heart defects and help prevent heart attacks. The new tool has the potential to revolutionize the medical industry because it is both faster and cheaper than t

4、he computer systems that are currently used by scientists to perform complex heart research. The system, detailed in a study in the August edition of the Journal of Computational Biology and Chemistry, is based on a video-game demo created by Simon Scarle two years ago when he was a software enginee

5、r at Microsoft“s Rare studio, the division of the U.S.-based company that designs games for the Xbox 360. Scarle modified a chip in the console so that instead of producing graphics for the game, it now delivers data tracking how electrical signals in the heart move around damaged cardiac cells. Thi

6、s creates a model of the heart that allows doctors to identify heart defects or conditions such as arrhythmia, a disturbance in the normal rhythm of the heart that causes it to pump less effectively. “This is a clever use of a processing chip . to speed up calculations of heart rhythm. What used to

7、take hours can be calculated in seconds, without having to employ an extremely expensive, high-performance computer,“ Denis Noble, director of Computational Physiology at Oxford University, tells TIME . To create a heart model now, researchers must use supercomputers or a network of PCs to crunch mi

8、llions of mathematical equations relating to the proteins, cells and tissues of the heart, a time-consuming and costly process. Scarle“s Xbox system can deliver the same results at a rate five times faster and 10 times more cheap, according to the study. “These game consoles aren“t just glorified to

9、ys. They are pieces of very powerful computing hardware,“ Scarle says. “I can see this . being most useful for students and early-career scientists to just quickly and cheaply grab that extra bit of computing power they otherwise wouldn“t be able to get.“ Scarle attributes his breakthrough creation

10、to his unusual background of working as a software engineer in the gaming industry and performing electrocardio-dynamics research at the University of Sheffield in England. The idea for the heart-modeling tool came from a “little shooter game“ he developed at Microsoft in which a player tries to gun

11、 down enemies in an arena meant to resemble a heart. “I did a game-ified version of my old cardiac code. I could actually present some “proper“ science based on the cool things us game developers do,“ Scarle says. The Xbox 360 isn“t the only video-game console that is being used for scientific resea

12、rch. At the University of Massachusetts campus in Dartmouth, scientists are using Sony PlayStations to simulate black-hole collisions to try to solve the mystery of what happens when a supermassive black hole swallows a star. So perhaps parents shouldn“t be too worried if their children are spending

13、 an inordinate amount of time playing video games. Who knows, today“s Grand Theft Auto or Halo addict may end up discovering a new moon around Saturn or finding a cure for cancer. PASSAGE TWO Since early November, cases of H1N1 have continued to decline nationwide, and scientists keeping track of th

14、e numbers say that as pandemics go, 2009 H1N1 may turn out to be a mild oneat least for the time being. The question now on health officials“ minds is: Will there be a second wave of cases in the new year? The answer depends on whom you ask. “We took an informal poll of about a dozen of some of the

15、world“s leading experts in influenza,“ Dr. Thomas Frieden, director of the Centers for Disease Control and Prevention (CDC), told reporters recently. “About half of them said, Yes, we think it“s likely that we“ll have another surge in cases. About half said, No, we think it“s not likely. And one sai

16、d, Flip a coin.“ It is an accurate reflection of how unpredictable the influenza virus can be. Although flu activity has been waning for the third week in a row, health officials warn that there are still four to five months left in the official influenza season, plenty of time for the virus to make

17、 its rounds and find new hosts. “The story of pandemics, and the story of H1N1 in general, is the story of persistent uncertainty where we never quite know what we are going to get or when,“ says Dr. Irwin Redlener, director of the National Center for Disaster Preparedness at the Columbia University

18、 Mailman School of Public Health. How severe the current H1N1 pandemic seems depends on what you use as a measuring stick. Compared with previous pandemics, like the 1918 Spanish flu, which killed 20 million people and infected up to 40% of the world“s population, or even the far less deadly 1957 an

19、d 1968 bouts with a strain of H1N1 influenza similar to the 2009 strain, things don“t seem as bad this time around. Fewer people are getting severely ill when infected, and fewer have died or required hospitalization from the flu than in previous pandemics. Marc Lipsitch, an epidemiologist at the Ha

20、rvard School of Public Health, and his colleagues studied the course of the 2009 H1N1 pandemic last spring in two citiesNew York and Minneapolisand determined that 0.048% of people who developed symptoms of H1N1 died, and 1.44% required hospitalization. Based on that data, published in PLoS Medicine

21、, Lipsitch anticipates far fewer deaths from 2009 H1N1 than was initially believed. By the end of the flu season in the spring of 2010, Lipsitch predicts, anywhere from 6,000 to 45,000 people will have died from H1N1 in the U.S., with the number most likely to end up between 10,000 and 15,000. Those

22、 estimates are far below the death toll of the 1957 flu, which killed 69,800 people in the U.S., according to government figures, and smaller also than the early predictions for the 2009 H1N1 flu deaths, which ranged from 30,000 to 90,000. It is not clear, however, that past pandemics are an appropr

23、iate gauge for evaluating the current flu or that the new projections are based on complete data. The eventual death toll of 2009 H1N1 may be less grim than the outcomes of previous pandemics, but it should be noted that 90 years ago, and even 40 years ago, health officials lacked the antiviral ther

24、apies and nationwide vaccination capabilities that are available today. That may have contributed to pandemics having a more devastating effect on the health of past populations. The new estimates are also less alarming than those providedalso by Lipsitchto the President“s Council of Advisers on Sci

25、ence and Technology last summer near the start of the pandemic. At the time, researchers had only patchy data on the number of people infected by, and seeking treatment for, the new flu. The initially bleak prediction of the impact of H1N1with up to 50% of the U.S. population becoming infected in th

26、e fall and winter of 2009, resulting in as many as 90,000 deathswas based on modeling of previous pandemics. Fortunately, the worst case scenario did not come to pass. “The worst case consistent with the data we have now is a lot milder than the worst case consistent with the data we had in the summ

27、er or spring,“ Lipsitch says. Still, Lipsitch and other health officials acknowledge that the 2009 H1N1 pandemic is not over. What worries health officials most is that as both seasonal and H1N1 flu viruses circulate among the population, the two strains could recombine into a more virulent and aggr

28、essive version that could cause more widespread illness and even death. How viruses behave once they nestle into a host is completely unpredictable, but scientists know that in a lab dish, seasonal and H1N1 flu strains mix and match readily. “I“m thinking we may have dodged a bullet here if in fact

29、we don“t get a more severe wave coming on the heels of the current wave,“ says Redlener. “But we“ll see what happens.“ A second wave could still prove more deadly than the seasonal flu, especially for young children. To date, 189 children have died of influenza in the U.S., the majority of them rela

30、ted to H1N1 infection, and that number is already higher than the total number of pediatric deaths attributed to flu in 2008. Lipsitch says that if current trends hold, H 1N 1 may end up causing as many influenza deaths, if not more, than the seasonal flu, which kills about 36,000 Americans each yea

31、r. Instead of hitting the elderly the hardest, though, most of the deaths may be among young children and infants. PASSAGE THREE The scientific name is the Holocene Age, but climatologists like to call our current climatic phase the Long Summer. The history of Earth“s climate has rarely been smooth.

32、 From the moment life began on the planet billions of years ago, the climate has swung drastically and often abruptly from one state to anotherfrom tropical swamp to frozen ice age. Over the past 10,000 years, however, the climate has remained remarkably stable by historical standards: not too warm

33、and not too cold, or Goldilocks weather. That stability has allowed Homo sapiens, numbering perhaps just a few million at the dawn of the Holocene, to thrive; farming has taken hold and civilizations have arisen. Without the Long Summer, that never would have been possible. But as human population h

34、as exploded over the past few thousand years, the delicate ecological balance that kept the Long Summer going has become threatened. The rise of industrialized agriculture has thrown off Earth“s natural nitrogen and phosphorus cycles, leading to pollution on land and water, while our fossil-fuel add

35、iction has moved billions of tons of carbon from the land into the atmosphere, heating the climate ever more. Now a new article in the Sept. 24 issue of Nature says the safe climatic limits in which humanity has blossomed are more vulnerable than ever and that unless we recognize our planetary bound

36、aries and stay within them, we risk total catastrophe. “Human activities have reached a level that could damage the systems that keep Earth in the desirable Holocene state,“ writes Johan Rockstrom, executive director of the Stockholm Environmental Institute and the author of the article. “The result

37、 could be irreversible and, in some cases, abrupt environmental change, leading to a state less conducive to human development.“ Regarding climate change, for instance, Rockstrom proposes an atmospheric-carbon-concentration limit of no more than 350 parts per million (p.p.m.)meaning no more than 350

38、 atoms of carbon for every million atoms of air. (Before the industrial age, levels were at 280 p.p.m.; currently they“re at 387 p.p.m, and rising.) That, scientists believe, should be enough to keep global temperatures from rising more than 2 above pre-industrial levels, which should be safely belo

39、w a climatic tipping point that could lead to the wide-scale melting of polar ice sheets, swamping coastal cities. “Transgressing these boundaries will increase the risk of irreversible climate change,“ writes Rockstrom. That“s the impact of breaching only one of nine planetary boundaries that Rocks

40、trom identifies in the paper. Other boundaries involve freshwater overuse, the global agricultural cycle and ozone loss. In each case, he scans the state of science to find ecological limits that we can“t violate, lest we risk passing a tipping point that could throw the planet out of whack for huma

41、n beings. It“s based on a theory that ecological change occurs not so much cumulatively, but suddenly, after invisible thresholds have been reached. Stay within the lines, and we might just be all right. In three of the nine cases Rockstrom has pointed out, howeverclimate change, the nitrogen cycle

42、and species losswe“ve already passed his threshold limits. In the case of global warming, we haven“t yet felt the full effects, Rockstrom says, because carbon acts gradually on the climatebut once warming starts, it may prove hard to stop unless we reduce emissions sharply. Ditto for the nitrogen cy

43、cle, where industrialized agriculture already has humanity pouring more chemicals into the land and oceans than the planet can process, and for wildlife loss, where we risk biological collapse. “We can say with some confidence that Earth cannot sustain the current rate of loss without significant er

44、osion of ecosystem resilience,“ says Rockstrom. The paper offers a useful way of looking at the environment, especially for global policy makers. As the world grapples with climate change this week at the U.N. and G-20 summit, some clearly posted speed limits from scientists could help politicians c

45、raft global deals on carbon and other shared environmental threats. It“s tough for negotiators to hammer out a new climate-change treaty unless they know just how much carbon needs to be cut to keep people safe. Rockstrom“s work delineates the limits to human growth-economically, demographically, ec

46、ologicallythat we transgress at our peril. The problem is that identifying those limits is a fuzzy scienceand even trickier to translate into policy. Rockstrom“s atmospheric-carbon target of 350 p.p.m, has scientific support, but the truth is that scientists still aren“t certain as to how sensitive

47、the climate will be to warm over the long-termit“s possible that the atmosphere will be able to handle more carbon or that catastrophe could be triggered at lower levels. And by setting a boundary, it might make policymakers believe that we can pollute up to that limit and still be safe. That“s not

48、the casepollution causes cumulative damage, even below the tipping point. By focusing too much on the upper limits, we still risk harming Earth. “Ongoing changes in global chemistry should alarm us about threats to the persistence of life on Earth, whether or not we cross a catastrophic threshold an

49、y time soon,“ writes William Schlesinger, president of the Cary Institute of Ecosystem Studies, in a commentary accompanying the Nature paper. But as the world attempts to break the carbon addiction that already has it well on the way to climate catastrophe, more clearly defined limits will be useful. But climate diplomats should remember that while they can negotiate with one another, ultimately, they can“t negotiate with the planet. Unless we manage our presence on Earth better, we may soon be in the last days of our Long Summer. PASSAGE FOUR Google may be valued at more