白勇 7-48

48, Wind resistance created by opening windows while driving results in a fuel penalty as great or greater than is incurred by using air conditioning.

a) as great or greater than is incurred by using air conditioning

b)that is as great or greater than is incurred using air conditioning

c)as great as or greater than that of using air conditioning

d)at least as great as air conditioning's

e) at least as great as that incurred by using air conditioning

本题的E选项是白勇指出的正确答案，我一直徘徊在C选项和E选项之间，因为这里的that肯定指代的是a fuel penalty，但是由于E选项使用的和主句的Wind resistance created by opening windows形式一样，我认为that在此可能产生歧义，也就是虽然逻辑上代表a fuel penalty，但是形式上已经代表了Wind resistance，谁能帮我解释一下这其中的玄机，谢谢了。

"虽然逻辑上代表a fuel penalty，但是形式上已经代表了Wind resistance"

为什么LZ会觉得形式上代表了Wind resistance呢？这不是it或者they那种代词指代，有优先次序的（先主语后宾语再从句主语之类的）。这里是比较对象，比的是什么，就是指代什么。

题中的对比：Wind resistance主语 （created by opening windows while driving定语，可以暂且不看） results in谓语 a fuel penalty宾语
            at least as great as
            that incurred by using air conditioning.

另外，C还有个明显的错误，as great as or greater than 是重复的，因为greater than就一定包括了as great as的意思了，OG上有讲，这种情况下用at least as great as才是正确的。