共用题干第一篇Arctic MeltEarth’s North and South Poles are famous for being cold a...

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问题共用题干第一篇

Arctic Melt

Earth’s North and South Poles are famous for being cold and icy.Last year,however,the amnount of ice
in the Arctic Ocean（北冰洋）fell to a record low.
Normally,ice builds in Arctic waters around the North Pole each winter and shrinks（缩小）during the
summer. But for many years,the amount of ice left by the end of summer has been declining.
Since 1979,each decade has seen an 11.4 percent drop in end?of-summer ice cover. Between 1981 and
2000,ice in the Arctic lost 22 percent of its thickness,becoming I.13 meters thinner.
Last summer,Arctic sea ice reached its thinnest levels yet.By the end of summer 2007,the ice had
shrunk to cover just 4.2 million square kilometers.That's 38 percent less area than the average cover at that
time of year. And it's a very large 23 percent below the previous record low,which was set just 2 years ago.
This continuing trend has made scientists concerned.
There may be several reasons for the ice melt, says Jinlun Zhang, an oceanographer（海洋学家）at the
University of Washington at Seattle.Unusually strong winds blew through the Arctic last summer. The winds
pushed much of the ice out of the central Arctic,leaving a large area of thin ice and open water.
Scientists also suspect that fewer clouds cover the Arctic now than in the past.Clearer skies allow more
sunlight to reach the ocean.The extra heat warms both the water and the atmosphere.In parts of the Arctic
Ocean last year,surface temperatures were 3.5℃warmer than average and 1.5℃warmer than the previous
record high.
With both air and water getting warmer,the ice is melting from both above and below. In some parts of
the Beaufort Sea,north of Alaska and western Canada,ice that measured 3.3 meters thick at the beginning
of the summer measured just 50 centimeters by season's end.
The new measurements suggest that melting is far more severe than scientists have seen by just looking
at ice covcrfrom above,says Donald K. Perovich,a geophysicist at the U.S.Army Cold Regions Research
and Engineering Laboratory in Hanover,N.H.
Some scientists fear that the Arctic is stuck in a warming trend from which it may never recover.

选项 What are the reasons for the ice melting according to the scientists? A:Strong winds and clear skits. B:Longer summers and shorter winters. C:Open water and thin ice. D:Heavy clouds and light winds.

答案 A

解析 build在此处是“增长，扩大”的意思。expand有“扩张”的意思，所以与build含义相符。
根据第四段第二句可知答案。
第五段的最后一句话和第六段的第一、二句话说明了科学家们推测的冰川融化的原因：一为强风，二为较少的云。
短文第七段举例说明在一个夏天冰层可以以令人难以置信的速度巡逗融化。
短文最后一句提到，一些科学家担心北极已经陷人可能永远无法恢复的变暖趋势之中。第二篇本文主要讲述了两个失聪的青少年之间的故事。

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共用题干第一篇Arctic MeltEarth’s North and South Poles are famous for being cold a...