第6篇 Arctic Melt
　　Earth's North and South Poles are famous for being cold and icy. Last year, however, the amount of ice in the Arctic Ocean fell to a record low1.
　　Normally, ice builds in Arctic waters around the North Pole each winter and shrinks 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 cover2. Between 1981 and 2000, ice in the Arctic lost 22 percent of its thickness -- becoming 1.13 meters thinner.
　　Last summer, Arctic sea ice reached its skimpiest 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. Andit's a very large 23 percent below the previous record low, which was set just 2 years ago. This continuing trend has scientists concerned.
　　There may be several reasons for the ice melt, says Jinlun Zhang, an oceanographer at the University of Washington3 in 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 water4.
　　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℃Celsius warmer than average and 1.5℃ warmer than the previous record high5.
　　With both air and water getting warmer, the ice is melting from both above and below. In some parts of the Beaufort Sea6, north of Alaska and western Canada, ice that measured 3.3m 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 cover from above, says Donald K. Perovich, a geophysicist at the U. S. Army Cold Regions Research and Engineering Laboratory in Hanover, N.H.7
　　Some scientists fear that the Arctic is stuck in a warming trend from which it may never recover.
　　詞匯：
　　Arctic n.北極，北極圈；adj.北極的
　　the Arctic Ocean 北冰洋 shrink v.萎縮；縮小，減少 oceanographer n.海洋學(xué)家 skimpy adj.缺乏的，不足的 centimeter n.厘米 geophysicist n.地球物理學(xué)家
　　注釋
　　1. fell to a record low: 跌到歷史最低點(diǎn)。record 作形容詞時(shí)，意思是“空前的，創(chuàng)記 錄的”。Record low 的反義詞是 record high: 歷史最高點(diǎn)。
　　2. ice cover: 冰覆蓋量
　　3. University of Washington: 華盛頓大學(xué)，創(chuàng)建于 l861 年，座落在美國華盛頓州西雅圖 市東北角，所以又稱西雅圖華盛頓大學(xué)，是美國著名的公立研究型大學(xué)。
　　4. open water: 沒有冰覆蓋的海面
　　5. record high : 見注釋1。
　　6. the Beaufort Sea: 波弗特海，是北冰洋邊緣海，位于美國阿拉斯加州東北岸和加拿大 西北岸，海中島嶼稀少，有無島海之稱。
　　7. Hanover，N．H：新罕布什爾州漢諾威市。N．H．是 New Hampshire 的縮寫。該州位于美 國新英格蘭地區(qū)。
　　練習(xí)：
　　1. Which of the following is closest in meaning to the word "build" in the first sentence of the second paragraph?
　　A) Construct. B) Extend. C) Create. D) Expand.
　　2. What is the ice cover in the Arctic by the end of 2007 summer?
　　A) 4.2 million square kilometers. B) 11.4 million square kilometers. C) 1.13 million square kilometers. D) 38 million square kilometers.
　　3. What are the reasons for the ice melt according to the scientists?
　　A) Strong winds and clear skies. B) Long summer and short winter.
　　C) Open water and thin ice. D) Light clouds and light winds.
　　4. Why is the ice melting from both above and below?
　　A) Because extra heat warms the air.
　　B) Because extra heat warms the water.
　　C) Because the temperature above the water is higher. D) Both A and B.
　　5. What can be a possible title for the passage?
　　A) What are scientists looking for in the Arctic Ocean? B) What are scientists doing in the Arctic Ocean?
　　C) Why are scientists worrying about the Arctic Ocean? D) Why are scientists interested in the Arctic Ocean?
　　練習(xí)：
　　1．D build 是個(gè)多義詞，四個(gè)選項(xiàng)都是該詞的潛在詞義。但在第二段的第一句中，build 與后半句中 shrink(become smaller)一詞相對(duì)，意思是 become bigger 之義。Extend 是增 長的意思，不適合用在此處。
　　2．A 答案可在第四段的第二句中找到。該句的意思是：2007 年夏末，冰的覆蓋面積已經(jīng) 縮小至 420 萬平方公里。
　　3．A 短文的第五和第六段回答了這個(gè)問題。第五段告訴我們，由于強(qiáng)風(fēng)的原因，大面積海 面僅有薄冰覆蓋或沒有冰層覆蓋。第六段告訴我們，晴朗的天空使太陽直接照射海面，導(dǎo)致 高溫。所以 A 是正確選擇。B 的內(nèi)容沒有在文中提到。C 的表述內(nèi)容是間接原因，是刮強(qiáng)風(fēng) 的結(jié)果。D 選項(xiàng)中，light clouds 的確是 ice melt 的原因，但 fight winds 是錯(cuò)誤的理解。
　　4．D 答案可在倒數(shù)第三段第一句話中找到。from both above and below 的意思是：無論 從海水上面還是底下，也就是說，無論是海水還是海面上的空氣。所以 A 和 B 都回答了問題 ： 高溫不但可能使水溫增高，也使氣溫增高。
　　5．C 本文描述了科學(xué)家對(duì)北冰洋冰覆蓋量的研究，研究結(jié)果是 Arctic is stuck in a warming trend from which it may never recover．(北冰洋變暖的趨勢可能不會(huì)逆轉(zhuǎn))。第四段最后一句說：This continuing trend has scientists concerned，短文最后一句也 告訴我們，科學(xué)家對(duì)這種趨勢十分憂慮(fear)。所以，C 是本題的答案。