-
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. 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.
查看答案
-
（单选题）海洋学家揭开了珊瑚礁颜色绚丽多变的秘密。原来，珊瑚虫体内负责控制色素生成的基因存在多种变异，激活的基因越多，珊瑚颜色就越明亮鲜艳。这些色素对与珊瑚共生并为之提供食物的海藻有保护作用。在日照强烈的地方，为了避免海藻被阳光杀死，珊瑚虫便会生成更多色素，珊瑚的颜色就会更鲜艳。最适合做这段文字标题的是：
A.保卫海藻
B.多彩珊瑚之谜
C.阳光与珊瑚
D.乐于奉献的珊瑚虫
-
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. It can be learned from the last sentence that _________.A:the ice melt in the Arctic may never stopB:scientists are trying hard to stop the ice melt in the ArcticC:scientists are delighted to find out what is going on in the ArcticD:the warming trend in the Arctic can be reversed in the near future
查看答案
-
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. The Beaufort Sea mentioned in Paragraph 7 is an example to show_________. A:how acetirate the new measurements areB:how thick the ice is in itC:how serious the problem of the ice melt in the Arctic isD:how dangerous it is to travel to it
查看答案
