专业八级-487及答案解析.doc

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1、专业八级-487 及答案解析(总分：100.00，做题时间：90 分钟)一、READING COMPREHENSIO(总题数：5，分数：100.00)The winner takes all as is widely supposed in computing circles. Indeed, geeks have coined a word, “Googlearchy“, for the way in which search engines encourage web traffic towards the most popular sites. The belief that searc

2、h engines make popular websites even more fashionable, at the expense of other pages, is now being challenged by research. The apparently magical ability of search engines such as Google to return relevant websites even when given the sketchiest of clues by the person entering a question relies on t

3、he use of mathematical recipes or algorithms. Google works by analyzing the structure of the web itself. Each of its billions of pages can link to other pages and can also, in turn, be linked to by others. If a page is linked to many other pages, it is flagged up as being important. Furthermore, if

4、the pages that link to this page are also important, then that page is even more likely to be important. The algorithm has been made increasingly complex over the years, to deter those who would manipulate their pages to appear higher in their rankings, but it remains at the heart of Google“s succes

5、s. Google is not alone in this. Many search engines take account of the number of links to a website when they return the results of a search. Because of this, there is a widespread belief among computer, social, and political scientists that search engines create a vicious circle that amplifies the

6、 dominance of established and already popular websites. Page returned by research engines are more likely to be discovered and consequently linked to by others. Not so, according to a controversial new paper that has recently appeared on ArViv, an online collection of physics and related papers. In

7、it, Santo Fortunato and his colleagues at Indiana University in America and Bielefeld University in Germany claim that search engines actually have an egalitarian effect that increases traffic to less popular sites. The researchers developed a model that described two extreme cases. In the first, pe

8、ople browsed the web only by surfing random links. In the second, people only visited pages that were returned by search engines. The researchers then turned to the real world. To their amazement, they found that the relationship between the two did not lie between the extremes suggested by their mo

9、del but somewhere completely different. It appears to show that the supposed bias in favor of popular pages is actually alleviated by the combination of search engines and people following random links. The paper, which was posted on ArViv for comment, has now come under attack. Matthew Hindman, a p

10、olitical scientist at Arizona Stake University, says that the data used in the research are pretty shoddy. Moreover, he says, the discrepancy between the model and the real world does not necessarily come from the role of the search engine. Whether Dr. Fortunato“s thesis stands the test of time rema

11、ins to be seen. That it is tested must be a good thing.（分数：20.00）(1).What“s the meaning of “deter“ in the second paragraph?（分数：5.00）A.Encourage.B.Dissuade.C.Delay.D.Support.(2).The foremost reason why Google is successful is no other than -|_|-.（分数：5.00）A.its magical ability of searching information

12、B.its higher page rankings and complex websitesC.complexity of its algorithms over the yearsD.its heavy web traffic and difficult structure(3).Santo Fortunato and his colleagues seem to suggest that -|_|-.（分数：5.00）A.fair effect is created by increasing traffic to less well known sitesB.popular websi

13、tes are made more fashionable by search enginesC.the situation in favor of popular pages has become more seriousD.popular pages are more likely to be discovered by random links(4).What determines the importance of a page?（分数：5.00）Three decades after the first Apollo landing on the moon, the debate b

14、etween proponents of manned and unmanned space missions has not changed a great deal. But many space scientists, who work with robotic satellites including me, have gradually moved from opposing human spaceflight to a more moderate position. In special situations, we now realized, sending people int

15、o space is not just an expensive stunt but can be more cost-effective than sending robots. Mars exploration is one of those cases. The basic advantage of astronauts is that they can explore Mars in real time, free of communications delays and capable of following up interesting results with new expe

16、riments. But the question arises: Where should the astronauts be? The obvious answeron the surface of Marsis not necessarily the most efficient. At the first “Case for Mars“ conference in 1981, one of the more provocative conclusions was that the Martian moons, Phobos and Deimos, could serve as comp

17、aratively inexpensive beachheads. Most current mission scenarios involve a pair of spacecraft. The first positions propellants and other heavy components, such as spare modules and re-entry vehicle, on or near Mars. Because the journey time is not crucial, it can use electric propulsion and gravity-

18、assist procedures to reduce the cost. The story is rather different for the second spacecraft, which transports the astronauts. It must traverse Earth“s radiation belts rapidly, and to save on supplies, the transit time to Mars should be as short as possible. The carious mission plans part ways when

19、 it comes to deciding what should happen once the crew ship and the freight ship link up at the Red Planet. In order of increasing difficulty and expense, six possible scenarios are: a Mars flyby analogous to the early Apollo missions, with immediate return to Earth; a Mars orbiter, permitting a lon

20、ger stay near the planet; a Phobos-Deimos (Ph-D) mission, involving a transfer to a circular, equatorial orbit, with a landing and base on a Martian moon, preferably Deimos; a hybrid mission (Ph-D-plus) that adds a brief sortie to the Martian surface; a full-scale Martian landing, with a longer stay

21、 on the surface and a complete program of research; and finally, an extended stay on Mars, during which astronauts erect permanent structures and commence continuous habitations of the planet. The trick will be to make sure the first manned mission is ambitiousthe adventure is, after all, part of th

22、e attractionbut not too ambitious, lest it not win funding. The Ph-D and Ph-D-plus missions offer a compelling balance of cost and benefit and would provide the greatest return for science. Deimos would offer an excellent base for the study of Mars. From there the astronauts could deploy and control

23、 atmospheric probes, subsurface penetrators and rover vehicles all over the Martian surface. The moon“s near-synchronous orbit permits direct contact with a rover for about 40 hours at a time. Phobos, being closer to the planet, orbits faster and therefore lacks this particular advantage. But astron

24、auts on either moon could analyze returned samples without fear of containing Earth with any Martian life-forms. The ready availability of a vacuum would make it easier to operate laboratory instruments such as mass spectrometers and electron microscopes. By relocating the spacecraft to different lo

25、cations on Deimosan easy task in the minuscule gravityastronauts could protect themselves from solar storms and meteor streams. Besides, the moons are fascinating bodies in their own right; direct sampling would investigate their mysterious origins. In comparison, an operating base on the surface of

26、 Mars would suffer many handicaps. Rovers deployed elsewhere on the planet would still have to be operated by remote control, which would require a satellite communications system to relay the commands. Returning samples from distant locations to the base would be more difficult. Heavy backup batter

27、ies or nuclear generators would be needed to power the base at night or during dust storms. In the more distant future, the moons could serve as way stations for descent to or ascent from the surface via tethers. Scientists on Deimos could safely direct large-scale climatological experiments, such a

28、s altering weather patterns or melting the polar capsthereby testing techniques for terraforming Mars or mitigating climate change on Earth. Although the costs and benefits of various mission scenarios are difficult to analyze at this early stage, I conducted a poll of Mars mission experts during a

29、conference several years ago. It offers the full spectrum of science more cheaply and quickly, and it would set the stage for an eventual base and colony on the surface.（分数：20.00）(1).Which of the following is NOT the characteristic of manned mission?（分数：5.00）A.A proper landing site has already been

30、chosen.B.Astronauts have the ability of exploring Mars in real time.C.There is no communications delays on the road.D.Astronauts design new experiments with interesting results.(2).Which of the following is INCORRECT as for the advantage of Ph-D and Ph-D-plus mission?（分数：5.00）A.Astronauts can analyz

31、e samples safely on Deimos and Phobos.B.Vacuum can protect astronauts from solar and meteor storms.C.Astronauts have no difficulties when landing on Mars surface.D.Astronauts may suffer many handicaps on the surface of Mars.(3).What is the most appropriate title of this article?（分数：5.00）A.Mars and i

32、ts MoonsB.To Mars by way of its MoonsC.Ambitious adventure: worthD.What it“s like on Mars(4).What allows a longer stay near the planet?（分数：5.00）As humankind moves into the third millennium, it can rightfully claim to have broken new ground in its age-old quest to master the environment. The fantasti

33、c achievements of modern technology and the speed at which scientific discoveries are translated into technological applications attest to the triumph of human endeavour. At the same time, however, some of these applications threaten to unleash forces over which we have no control. In other words, t

34、he new technology Man now believes allows him to dominate this wider cosmos could well be a Frankenstein monster waiting to turn on its master. This is an entirely new situation that promises to change many of the perceptions governing life on the planet. The most acute challenges facing the future

35、are likely to be not only those pitting man against his fellow man, but those involving humankind“s struggle to preserve the environment and ensure the sustainability of life on earth. A conflict waged to ensure the survival of the human species is bound to bring humans closer together. Technologica

36、l progress has thus proved to be a double-edged sword, giving rise to a new form of conflict: a clash between Man and Nature. The new conflict is more dangerous than the traditional one between man and his fellow man, where the protagonists at least shared a common language. But when it comes to the

37、 reactions of the ecosystems to the onslaught of modern technology, there is no common language. Nature reacts with weather disturbances, with storms and earthquakes, with mutant viruses and bacteriathat is, with phenomena having no apparent cause and effect relationship with the modern technology t

38、hat supposedly triggers them. As technology becomes ever more potent and Nature reacts ever more violently, there is an urgent need to rethink how best to deal with the growing contradictions between Man and Nature. For a start, the planet, and hence all its inhabitants, must be perceived as an inte

39、gral whole, not as a dichotomous mass divided geographically into the rich and developed and the poor and underdeveloped. Today, globalization encompasses the whole world and deals with it as an integral unit. It is no longer possible to say that conflict has shifted from its traditional east-west a

40、xis to a north-south axis. The real divide today is between summit and base, between the higher echelons of the international political structure and its grassroots level, between governments and NGOs, between state and civil society, between public and private enterprise. The mesh structure is part

41、icularly obvious on the Internet. While it is true that to date the Internet seems to be favouring the most developed sectors of the international community over the less developed, this need not always be the case. Indeed, it could eventually overcome the disparities between the privileged and the

42、underdeveloped. On the other hand, the macro-world in which we live is exposed to distortions because of the unpredictable side-effects of a micro-world we do not and cannot totally control. This raises the need for a global system of checks and balances, for mandatory rules and constraints in our d

43、ealings with Nature, in short, for a new type of veto designed to manage what is increasingly becoming a main contradiction of our time: the one between technology and ecology. A new type of international machinery must be set in place to cope with the new challenges. We need a new look at the harne

44、ssing of scientific discoveries, to maximize their positive effects for the promotion of humanity as a whole and to minimize their negative effects. We need an authority with veto powers to forbid practices conducive to decreasing the ozone hole, the propagation of AIDS, global warming, desertificat

45、ionan authority that will tackle such global problems. There should be no discontinuity in the global machinery responsible for world order. The UN in its present form may fall far short of what is required of it, and it may be undemocratic and detrimental to most citizens in the word, but its absen

46、ce would be worse. And so we have to hold on to the international organization even as we push forward for its complete restructuring. Our best hope would be that the functions of the present United Nations are gradually taken over by the new machinery of veto power representing genuine democratic g

47、lobalization.（分数：20.00）(1).Which of the following divisions is NOT considered a dichotomous mass?（分数：5.00）A.The east and the west.B.The developed and the undeveloped.C.The north and the south.D.The governments and the nongovernmental organizations (NGOs).(2).According to the passage, which is NOT a

48、responsibility of the proposed international authority?（分数：5.00）A.Monitoring effects of scientific discoveries.B.Dealing with worldwide environmental issues.C.Vetoing human attempts to conquer Nature.D.Authorizing efforts to improve human health.(3).When commenting on the present role of the UN, the

49、 author expresses his -|_|-.（分数：5.00）A.dissatisfactionB.disillusionmentC.objectionD.doubt(4).What has technological progress led to?（分数：5.00）It“s hard to miss them: the epitome of casual “geek chic“ and organized within the warranty of their Palm Pilots, they sip labor-intensive caf latts, chat on sleek cell phones and ponder the road to enlightenment. In the US they worry about the environment as they drive their gas-guzzling sports utility vehicles to emporiums of haute design to buy a $50 titanium spatula; they think about their tech