2. 外语
  3. If you’ve been following the status of Arctic sea ice for the past few years, hearing scientists【C1】______the potential coming o

If you’ve been following the status of Arctic sea ice for the past few years, hearing scientists【C1】______the potential coming o

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问题     If you’ve been following the status of Arctic sea ice for the past few years, hearing scientists【C1】______the potential coming of an ice-free Arctic summer may sound like old news. But according to researchers at NASA and the National Snow and Ice Data Center(NSIDC), this year, sea ice at the【C2】______of the globe may be even more【C3】______to melting than in the past.
    Each winter as the sun sets for several months and temperatures begin to plummet(骤降), the Arctic ice cap grows, reaching its【C4】______extent in March. The melting season then begins, with the ice minimum extent occurring in September.
    But all sea ice is not created equal. Multi-year ice is sea ice that has【C5】______at least one melt season and is typically 2 to 4 meters(6.5 to 13 feet)thick. First-year ice, on the other hand, has accumulated over only one【C6】______and is much thinner. As the 2009 melt season begins, satellite data shows that the Arctic Ocean is covered【C7】______by first-year and second-year ice, which means the thin ice is less likely to survive the coming summer.
    The maximum sea ice extent for winter of 2008-2009, which was reached on February 28, was 278 000 square miles less than the【C8】______extent for 1979-2000 and represented the fifth lowest maximum ice extent on【C9】______Although the ice extent is important, ice thickness is the best overall【C10】______of Arctic ice cover health.
A)survived F)hardly K)mostly
B)resistant G)vulnerable L)center
C)announce H)diminished M)maximum
D)season I)record N)performance
E)indicator J)average O)top
【C7】
选项
答案K
解析
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