下面的短文后有兩項測試任務(wù)：(1)第23——26題要求從所給的6個選項中為第2——5段的每段選擇l個最佳標(biāo)題;(2)第27——30題要求從所給的6個選項中為每個句子確定1個最佳選項。

　　Global Warming

(1) Smoke is clouding our view of global warming, protecting the planet from perhaps three-quarters of the greenhouse (溫室) effect. That might sound like good news, but experts say that as the cover diminishes in coming decades, we are facing a dramatic increase of warming that could be two or even three times as great as official best guesses.

(2) This was the dramatic conclusion reached last week at a workshop in Dahlem, Berlin, where top atmospheric scientists got together, including Nobel prize winner Paul Crutzen and Swedish scientist Bert Bolin, former chairman of the UN's Intergovemmental Panel on Climate Change (IPCC).

(3) IPCC scientists have suspected for a decade that aerosols (浮質(zhì)) of smoke and other particles from burning rainforest, crop waste and fossil fuels are blocking sunlight and counteracting the warming effect of carbon dioxide (二氧化碳) emissions. Until now, they reckoned that aerosols reduced greenhouse warming by perhaps a quarter, cutting increases by 0.2℃. So the 0.6℃ of warming over the past century would have been 0.8℃without aerosols.

(4) But the Berlin workshop concluded that the real figure is even higher--aerosols may have reduced global warming by as much as three-quarters, cutting increases by 1.80C. If SO, the good news is that aerosols have prevented the world getting almost two degrees warmer than it is now. But the bad news is that the climate system is much more sensitive to greenhouse gases than previously guessed.

(5) As those gases are expected to continue accumulating in the atmosphere while aerosols stabilize or fall, that means "dramatic consequences for estimates of future climate change",the scientists agreed in a draft report from the workshop.

23——26概括大意

23. Paragraph 2 __________

24. Paragraph 3 __________

25. Paragraph 4 __________

26. Paragraph 5 __________

A. Atmospheric scientists

B. The calculations made at the berlin workshop

C. The previous calculations of the effect of aerosols

D. The scientists' agreement

E. The authoritative conclusion

F. Greenhouse gases

27——30完成句子

27. When the cover diminishes in the coming decades, temperature __________.

28. The conclusion reached at the Berlin workshop __________.

29. The Berlin workshop concluded that the real figure __________.

30. The increase of greenhouse gases __________.

A. will influence future climate change

B. was somewhat surprising

C. will rise rapidly

D. was known to us all

E. was much higher than had been expected

F. will drop dramatically

參考答案：

23.E。文章第三段指出，結(jié)論是由杰出的大氣科學(xué)家得出的?！敖艹龅目茖W(xué)家”即權(quán)威科學(xué)家。

24.C。文章第三段提到了對浮質(zhì)所產(chǎn)生的影響進行的計算。這個計算先于第四段所提及的計算，因而被稱為“先前的”計算。

25.B。文章第四段開頭指出，“然而，柏林討論會得出的結(jié)論是，真正的數(shù)字比這還要高——浮質(zhì)可能已經(jīng)把全球氣候變暖的情況減少了3/4。”因此，本段講的是柏林討論會的計算。

26.D。第五段講的是科學(xué)家們關(guān)于浮質(zhì)對氣候變化影響的一致性的看法。

27.C。文章第一段指出，隨著在未來幾十年里這種煙霧覆蓋物的不斷減少，我們會面臨驚人的氣候變暖的情況，也就是說，覆蓋物減少，氣溫會迅速升高。

28.B。柏林討論會的結(jié)論有點令人吃驚，因為這個結(jié)論認為，浮質(zhì)可能已經(jīng)把全球氣候變暖的情況減少了3/4，這個數(shù)字是驚人的。

29.E。文章第四段指出，“然而，柏林討論會得出的結(jié)論是，真正的數(shù)字比這還要高?！薄氨冗@還要高”是說比第三段推測的數(shù)字要高，也就比人們預(yù)期的要高。

30.A。文章的最后一段提到了這個問題：這些氣體(溫室氣體)在大氣里不斷聚積對未來氣候變化的預(yù)測產(chǎn)生驚人的結(jié)果。