阅读下面的短文。每篇短文的后面有五个问题，每个问题有四个备选答案。请根据短文的内容选择最佳答案。每个试题计3分,共计15分
A Sunshade for the Planet
Even with the best will1 in the world，reducing our carbon emissions is not going to prevent global warming．It has become clear that even if we take the most strong measures to control emissions，the uncertainties in our climate models still lea'ye open the possibility of extreme warming and rises in sea level．At the same time，resistance by governments and special interest groups makes it quite possible that the actions suggested by climate scientists might not be implemented soon enough．
Fortunately，if the worst comes to the worst2，scientists still have a few tricks up their sleeves3．For the most part they have strongly resisted discussing these options for fear of inviting a sense of complacency that might thwart efforts to tackle the root of the problem．Until now，that is．A growing number of researchers are taking a fresh look at large-scale “geoengineering” projects that might be used to counteract global warming．“I use the analogy of methadone4,” says Stephen Schneider，a climate researcher at Stanford University in California who was among the first to draw attention to global warming．“If you have a heroin addict，the correct treatment is hospitalization，and a long rehab． But if they absolutely refuse，methadone is better than heroin．”
Basically the idea is to apply “sunscreen” to the whole planet．One astronomer has come up with a radical plan to cool Earth；launch trillions of feather-light discs into space，where they would form a vast cloud that would block the sun’s rays．It’s controversial，but recent studies suggest there are ways to deflect just enough of the sunlight reaching the Earth’s surface to counteract the warming produced by the greenhouse effect．Global climate models show that blocking just 1．8 per cent of the incident energy in the sun’s rays would cancel out the warming effects produced by a doubling of greenhouse gases in the atmosphere． That could be crucial，because even the most severe emissions-control measures being proposed would leave us with a doubling of carbon dioxide by the end of this century，and that would last for at least a century more．
词汇：
emission/i5miFEn/n．发射，发射物 heroin/5herEuin/n．海洛因
complacency/kEm5pleIsEnsI/n．满足 hospitalization/7hCspitElai5zeiFEn /
n．住院治疗
thwart/WwC:t/v．反对，阻绕 rehab/ri:hAb/n．接受康复治疗
geoengineering n．地质工程 astronomer/ E5strRnEmE(r)/n．天文学家
trillion/ 5triljEn/n．(英、德) counteract/7kauntE5rAkt/v．抵消；抵制
百万兆(1018)；(美、法) 万亿，兆 (1012)
controversial/7kCntrE5vE:FEl /analogy/E5nAlEdVi/n．类似；模拟
adj．有争议的
deflect/di5flekt/v．(使)偏转 methadone/ 5meWEdEun/n．美沙酮，美散痛
注释：
1． the best will：最好的愿望
2． if the worst comes to theworst：如果最最糟糕的事情发生了。这是英式英语的用法，在美式英语中它说成if worst comes to worst。在不同的语境中，有不同的泽法，如：“If the worst comes to the worst，”Becky thought，“my retreat“secure；and l have the right- hand seat inthe barouche．”蓓墓想道：“逼到最后一条路，逃难是不怕的了，在他的大马车里，我稳稳地有一个位子了。”又如：Ifthe worst comes to the worst，we’ll sell the car．大不了我们把车卖了。
3． scientists still have a few tricks叩their sleeves：科学家们仍然有些不为人所知的招数。 have something up one’s sleeve是英语成语，意思是：to have a secret idea or plan，有锦囊妙计，有所保留的，秘而不宣的谋略或计划，例如：If this trip doesn’t work out I’ve still got a few ideas up my sleeve．
4． methadone：美沙酮，一种有效的合成麻醉药，它不像口马啡或海洛因那样容易汁人上瘾，在戒毒治疗中被用作这些毒品的替代品。
责任编辑：wangpeng6151
