大学六级-430及答案解析.doc

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1、大学六级-430 及答案解析(总分：703.00，做题时间：90 分钟)一、BPart Writing(总题数：1，分数：106.00)1. 1简要分析图表 2分析观众喜欢看体育节目的原因 BWhy Do the Viewers Like Watching Sport Programs?/B （分数：106.00）_二、BPart Reading (总题数：1，分数：70.00)BEarth: Melting in the Heat?/BGlaciers are melting; the ice caps are disappearing into the oceans; sea levels

2、 may rise by many meters as a consequence. Indigenous (本土的) Arctic peoples will find their food stocks gone, while fresh water supplies in Asia and south America will disappear as the glaciers which provide them melt away; penguins, polar bears and seals will find their habitats gone, their traditio

3、nal lives unlivable.But how realistic is this picture? Is the worlds ice really disappearing, or is it unscientific hot air?A European satellite named Cryosat was designed to provide definitive answers to some of these questions. A launcher fault destroyed the mission in October 2005, but the Europe

4、an Space Agency has approved a replacement. In the meantime, here is our global snapshot.BThe Antarctic/BHuge, pristine (质朴的), dramatic, unforgiving-the Antarctic is where the biggest of all global changes could begin.There is so much ice here that if it all melted, sea levels globally would rise hu

5、gelyperhaps as much as 80m. Say goodbye to London, New York, Sydney, Bangkok in fact, the majority of the worlds major cities.But will it happen? Scientists divide the Antarctic into three zones: the east and west Antarctic ice sheets; and the Peninsula, the tongue of land which points up towards th

6、e southern tip of South America.“Everybody thinks that the Antarctic is shrinking due to climate change, but the reality is much more complex,“ says David Vaughan, a principal investigator at the British Antarctic Survey in Cambridge, U.K. “Parts of it appear to be thickening as a result of snowfall

7、 increases, but the Peninsula is thinning at an alarming rate due to warming. The West Antarctic sheet is also thinning, and were not sure of the mason why.“BOn the Up/BTemperatures in the Peninsula appear to be increasing at around twice the global averageabout 2 over the last 50 years. Those figur

8、es are based on measurements made by instruments at scientific stations.Earlier this year, David Vaughans group published research showing that the vast majority of glaciers along the Peninsula87% of the 244 studiedare in retreat. The ice dumped into the ocean as the glaciers retreat should not make

9、 much difference to global sea levelsperhaps a few centimeters.More worrying, potentially, are the vast ice sheets covering the rest of Antarctica. Making temperature measurements for the continent as a whole is difficult; it is a vast place-more than 2,000 km across-them are few research stations,

10、and temperatures vary naturally by 23 from year to year. But measurements indicate that in the west, reciting is underway.“About one-third of the West Antarctic ice sheet is thinning,“ says Dr. Vaughan, “on average by about 10cm per year, but in the worst places by 34m per year.“The rock on which th

11、e West Antarctic ice rests is below sea level, and British Antarctic Survey researchers believe the thinning could be due to the ice sheet melting on its underside.“It may be that the ocean is warming and thats causing the ice to melt, but there may be other reasons as well; for example, theres lots

12、 of volcanism in that area and so that could change how much heat is delivered to the underside of the ice sheet.“Cryosat should help to pin down what is happening at the West Antarctic fringe. The radar altimeters on board its predecessors ERSI and ERS2 have been unable to map the steep slopes at t

13、he coast, whereas Cryosats instrument should be able to cope.If the entire West Antarctic ice sheet did melt, sea levels globally would rise, by around 5m. But at the moment, there is no sign of that happening.One recent scientific paper attempted to calculate probabilities for how much West Antarct

14、ic melting would contribute to global sea-level rises during this century. The conclusions: a 30% probability of a 20 cm rise, and a 5% chance of a 1m rise.Eastern MassAnd what of the big monster, the much larger East Antarctic sheet? A recent study using altimeter data suggested it is getting thick

15、er, by about 1.8 cm/yr; another, using the gravity satellite mission Grace indicates its mass remains stable. But could rising temperatures in time drain the ice away?“It is net going to happen on any realistic human timescale,“ says David Vaughan. “Its so cold that you could raise temperatures by 5

16、10 without having much of an impact; its on rock above sea level, so warming in the ocean cant affect it.“Largely insulated from global trends and so big as to generate its own climatic systems, most of Antarctica appears to be immune to the big melt for now, though answers to what is happening in t

17、he west are eagerly awaited.BThe Arctic/BAt the top of the world, the Arctic is a region built on water. Around the Noah Pole is ocean, with ice floes crowding in each winter and thinning again in the summers.In September, we learned from scientists at the U.S. National Snow and Ice Data Center that

18、 the extent of ocean covered by ice is getting smaller each year, the current rate of shrinkage they calculate at around 8% per decade. Their projection is that within about 60 years, there will be no summer ice at all on the Arctic Ocean.“Overall, the extent has been declining, with some oscillatio

19、ns (摆动), since the 1970s when satellites were able to map it,“ comments Peter Wadhams, Professor of Ocean Physics at Cambridge University, U.K., and currently at the Laboratoire Oce anographique in Villefranche-sur-mer, France. “Theres been a slow decline, but now the thinning appears to be more rap

20、id. In the last two decades, not only has the area shrunk but the ice has got thinner by about 40%; the prediction is that it will vanish altogether during summers in the second half of this century.“BMilitary Records/BMeasurements of thickness come mainly from military submarines, which spent long

21、periods under the Arctic ice during the Cold War.Peter Wadhams was one of the scientists who afterwards persuaded the authorities in Britain and the United States to declassify their data.But as a method of measurement, it is far from perfect; and satellites have given only limited help. The existin

22、g satellite fleet gives good measurements of ice extent, but is not so good at detecting thickness, partly because the orbits of satellites with radar altimeters do not cover every portion of the ocean.This data deficit has led to a rival theorythat the ice is not melting at ail; it is simply piling

23、 up in another part of the ocean, perhaps along the north Canadian coast.Peter Wadhams believes he has now disproved this idea. “We did an experiment where we installed a set of buoys (浮标) in that region which measure the thickness of the ice and transmit it back via satellite,“ he says. “The buoy s

24、its on the ice, and as waves pass under it they make it rise and fall, just by a millimeter or two; measuring this allows you to calculate the thickness of the ice.“The preliminary results, announced at a scientific meeting in April 2005, show that the extra ice is not there; it really has melted aw

25、ay.BWider Impact/BTo people living, in the region, the melting brings mixed news. Current lifestyles and staple foods will almost certainly change, but the open ocean may permit new opportunities for trade and agriculture.A bigger question is what it means for the rest of the planet. Ice reflects th

26、e suns radiation; water absorbs it. More water and less icea lower albedo (反照率)mean that the pace of warming could increase. In this scenario, the Earth would be losing one of its “natural checks and balances“ against warminganother positive feedback mechanism.The Arctic is intimately tied to the gl

27、obal climate system, and disruptions here have the potential to create worldwide changesalbeit (虽然) over long timescales. Possibly the most powerful link is via the thermohaline (热盐的) circulation, the global conveyor taking warm water along ocean surfaces and returning colder water at depth.“One ver

28、y sensitive place is the middle of the Greenland Sea,“ says Peter Wadhams. “That has been ice-free in the summer, but usually in winter it would be covered by a lobe of ice growing out from the Greenland coast. AS it formed, it rejected salt back into the water, making the water heavier and helping

29、it to sink. Since 1997, the ice tongue has never termed. That will be having an impact on the thermohaline circulation.“Back in geological history, about 55 million years ago, the Arctic was a warm (possibly 20C) shallow sea that would have been ice-free without the intervention of a human-enhanced

30、greenhouse effect.Natural variations may be playing a role in the picture seen now; hut, as with other parts of the planet, it is the speed of change that alarms many researchers as much as the change itself.（分数：70.00）(1).Fresh water supplies in Asia and south America is disappearing as the glaciers

31、 melt away.（分数：7.00）填空项 1:_(2).If all the ice in the Antarctic melted, global sea levels would rise hugely.（分数：7.00）填空项 1:_(3).According to David Vaughan, the Antarctic is shrinking due to climate change.（分数：7.00）填空项 1:_(4).David Vaughans group found that most of the glaciers along the Peninsula wer

32、e in retreat.（分数：7.00）填空项 1:_(5).Cryosat should help figure out what is happening at the West Antarctic fringe because its radar altimeters should be able to _.（分数：7.00）填空项 1:_(6).Most of Antarctica appears to be immune to the big melt for now because its largely insulated from global trends and its

33、 so big as to generate _.（分数：7.00）填空项 1:_(7).According to scientists at the U.S. National Snow and Ice Data Center, within about 60 years, there will be _ on the Arctic Ocean.（分数：7.00）填空项 1:_(8).The existing satellites are not good at detecting the thickness of the ice partly because the orbits of s

34、atellites with _ do not cover every portion of the ocean.（分数：7.00）填空项 1:_(9).To people living in the Arctic, the melting of some glaciers may permit new opportunities for _.（分数：7.00）填空项 1:_(10).The ice tongue growing out from the Greenland coast used to reject salt back into the water, making _ heav

35、ier and helping it to sink.（分数：7.00）填空项 1:_三、BPart Listenin(总题数：3，分数：105.00)BQuestions 11 to 18 are based on the conversation you have just heard./B（分数：56.00）A.She broke the microphone:B.She was interrupted by a phone call during her presentation.C.She is planning to give her presentation as soon as

36、 the microphone is fixed.D.The microphone broke just as she began her presentation.A.One month,B.One month and a half.C.Two months.D.Two months and a haleA.She should live in the country.B.She should live near the spring.C.He prefers to live in the country.D.He agrees with the woman.A.It is the best

37、 city hes ever visited.B.It was worse than he had expected.C.It is difficult to get around in the city.D.The hotel service is terrible in the city.A.He will choose a new topic to write the essay.B.He will choose the novel written by Shakespeare as the topic.C.He refuses to accept the mans advice.D.H

38、e is on the wrong track.A.Paper plates are cheaper than dishes.B.Dishes break more easily than paper plates.C.There is no need to wash any dishes now.D.The womans roommate will return soon.A.She has not applied for any university yet.B.She will begin university classes in a few weeks.C.She does not

39、know yet if a university will accept her.D.She is too busy to contact the university right now.A.Reconsider his position later.B.Allow the student to miss class.C.Lower the students grade.D.Suggest that the student try to reschedule the operation.BQuestions 19 to 21 are based on the conversation you

40、 have just heard./B（分数：21.00）A.Its a market.B.Its a recreation center.C.Ifs an algebra school.D.Its the name of a part-time job.A.Six.B.Seven.C.Five.D.Six or seven.A.It doesnt move at all.B.It moves much faster than regular lines.C.Its next to the regular lines.D.Its her favorite.BQuestions 22 to 25

41、 are based on the conversation you have just heard./B（分数：28.00）A.Lower prices.B.More choices.C.More competition.D.More companies.A.Other American states.B.Foreign countries.C.Regions outside the city where people live.D.Other cities in the state where people live.A.Its run by the government.B.It app

42、eals to most people.C.It offers much choice.D.Its a monopoly.A.Shell pay per minute.B.Shell pay a monthly service fee.C.Shell pay a yearly service fee.D.She wont have to pay.四、BSection B/B(总题数：3，分数：70.00)BPassage OneQuestions 26 to 28 are based on the passage you have just heard./B（分数：21.00）A.Becaus

43、e they are too small to understand the rules.B.Because they are absent-minded.C.Because they dont have much time for it.D.Because they arc not interested in it.A.A camera.B.A film.C.A photo.D.A picture.A.Time.B.Memory.C.Habit.D.Textbook.BPassage TwoQuestions 29 to 31 are based on the passage you hav

44、e just heard./B（分数：21.00）A.Botany is a very ancient learning.B.People in the Stone Age knew a lot about plants.C.People in the Stone Age knew little about plants.D.Pre-industrial societies have little insights about plants.A.People who live in Amazon tribes dont think plants are the basis of the foo

45、d pyramid.B.People who live in Amazon tribes dont regard botany as a special branch of knowledge.C.People who live in Amazon tribes know all the properties of plants in the jungle.D.People who live in Amazon tribes give some special names to botany.A.Agriculture in the industrialized world.B.Cultiva

46、ted crops.C.The association between roses and humans.D.The discoveries of certain grasses.BPassage ThreeQuestions 32 to 35 are based on the passage you have just heard./B（分数：28.00）A.Almost one million.B.About 600 thousand.C.Nearly 400 thousand.D.Approximately 200 thousand.A.Residential area.B.Shoppi

47、ng centers.C.Parking lots.D.Shopping centers or parking lots near stadiums or gymnasiums.A.They have to break into the car.B.Five percent of the cars are left unlocked.C.They sometimes find car keys in the ignition and simply get in.D.They knock out the driver and get the car away.A.Young people who

48、 want to ride a car for joy.B.Professionals who steal cars for other crimes.C.People who lack money to buy a car.D.Both A and B.五、BSection C/B(总题数：1，分数：77.00)There is something hard toU (36) /Uabout cherries. The small red fruit is a popularU (37) /Ufood around the world. In northern areas, cherry trees are just beginning to produce flowers.Cherries are thought to be native to western Asia. There