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题库 / GMATAdvanced-CR-37
Ozone in the stratosphere blocks deadly ultraviolet rays from the sun, but chlorofluorocarbons (CFCs) in aerosols and other products have thinned this protective layer. Evidence of this is the ozone hole that forms over the South Pole every Antarctic spring as temperatures drop below – 78 ° C, the temperature at which ozone depletion occurs. Measurements of the ozone hole taken at various times this spring show that, compared with the same times the previous year, its area diminished by four million square kilometers. Nevertheless, scientists have not concluded that the ozone layer is recovering.
Which of the following would, if true, provide the strongest reason for the scientists’ reaction to the measurements?
The ozone hole has steadily grown in size every year for the past decade except this year.
The length of time that the ozone hole persists fluctuates from year to year.
As a result of international treaties, CFCs have been completely banned for several years.
Weather patterns allowed unusual amounts of warm air to mix into the polar regions this year.
Human-made CFCs retain their ability to destroy ozone molecules for seventy-five to one hundred years.
逻辑关系：温度降至-78°C以下，臭氧洞形成；-->今年测了几次不同的时间都发现臭氧洞小了；-->但这不并不能证明臭氧洞正在恢复。
ABC都无关；E 反应不出这个逻辑关系，这个逻辑关系的核心是：“洞突然变小”，而D正好解释了个这个关系-->有某些温室气体混入（温室气体混入-->导致温度上升-->暂时性地影响了今年的臭氧洞的形成）
its area diminished by four million square kilometers 第一遍its理解成ozone然后看出不正确答案也是服了自己。。。
呵呵，自己脑补温度【升高】导致ozone hole形成，人家明明白白写着the ozone hole that forms over the South Pole every Antarctic spring as temperatures drop below – 78 ° C，温度【降低】到-78°以下的时候ozone hole形成。
问削弱→证明【今年ozone hole减小不能代表ozone layer修复，即不是常规的温度升高造成的】
D项 今年温度升高不是常规升高，而是异常的暖空气涌入
我老是喜欢加入自己的常识认知。。。
提到了今年tested at various times，说明测试了很多次，每次都同比减少，排除了B的由于hole persist的时间长度问题。
证明没有变好的原因一定与premise的内容相关
洞fluctuations 不能证明就不是变好了
之前都是恶化今年突然变好了不能否定她变好了
臭氧的洞减少了，但是科学家并不认为臭氧层recover了。问原因。因为今年有不寻常的热空气。
zone hole dimished！！！
The hole forms when the temperature drops below –78°C during the Antarctic spring. If much of the area where the hole appears was significantly warmer than the previous year—perhaps above –78°C—there exists a reason other than a recovery in the ozone layer that explains the smaller size of this year's hole in the ozone. This would support the scientists' skepticism.