1/ identify the right-hand element (= the one that follows the comparison signal)
2/ ask yourself whether this element SHOULD be part of the comparison, according to context/common sense. (There are no "omissions" here. if the stuff following the signal isn't actually compared to something else, the sentence is wrong.)
3/ if so, try to find something that matches it on the other side. if you find such a thing, you're good.右边的所有成分必须在左边找到，包括介词短语。
o judge "beauty contests" among answer choices, on the other hand, all you need is the simple ability to say "this looks more like X than that does".
他举了例子：) Oil prices were higher in 2007 than in 2008.
àadv. vs. adv. 正确
c) Oil prices were higher in 2007 than oil prices in 2008.noun modifer而第一个是副词modifer，所以错误。
我想问oil prices in 2007 were higher than in 2008 对不对？in 2008能不能看成是noun modifier？？
因为有一题是这样：
ccording to public health officials, in 1998 Massachusetts became the first state in which more babies were born to women over the age of thirtythan under it.
对于楼主的疑问，写出我的个人理解，希望有帮助。我在另一个帖子前后比较如何省略四楼里提过这种观点，二楼有Ron的链接。我个人做题，第一原则就是parallelism，或者翻译为对仗。这里比较的是over the age of thirty和under it，都是介宾结构，可以看作是women的后置定语，所以选择A。C中they指代不明，可以是women，可以是babies。DE时态不对，应该用一般过去时就可以了，和were born to 同时发上在1998年。B我虽然知道不对，但暂时还讲不清是哪个语法点，希望NN能来指教。