A一定为正确答案,比较两项: A项:Discussion of greenhouse effects has usually focused on whether the Earth would warm and by how much, but climatologists have indicated all along that the most obvious effects, and those that would have the largest impact on people, would be extremes of temperature, precipitation, and storminess. E项:Discussion of greenhouse effects has usually focused on whether the Earth would warm and by how much, but climatologists have indicated all along that extremes of temperature, precipitation, and storminess, which are the most obvious effects, are those to impact the most on people. A项:关于温室效应的讨论集中在...,但是气象学家指出最明显的效应是… E项,关于温室效应的讨论集中在...,但是气象学家指出...是影响人们最大的。 很明显,A为正确选项。因为A紧紧围绕关于温室效应的讨论,用but来对比。而E项,but后的气象学家指出的东西与前面的不是一个问题。所以如果选E项,but就没有道理存在。 |