有个不太明白的语法点请教大家，比较，以prep的第一题为例

之前一直没注意过比较的问题后来发现我总是找不好对象对称的问题，而且越这么觉得越发现比较的问题好多呀...

unlike的结构没有问题，只要是as...as，more（...）than结果，后面的部分总会出问题

尤其是判断要不要加助动词，要不要加that of/those of的时候总会错，结果现在看到这种题就发慌

能不能麻烦经验丰富的同志给系统总结一下呢？

用一道只要看过prep的人都见过的一道题举例子

To meet the rapidly rising market demand for fish and seafood, suppliers are growing fish twice as fast as their natural growth rate, cutting their feed allotment by nearly half and raising them on special diets.

(A) their natural growth rate, cutting their feed allotment
(B) their natural growth rate, their feed allotment cut
(C) growing them naturally, cutting their feed allotment
(D) they grow naturally, cutting their feed allotment
(E) they grow naturally, with their feed allotment cut

这道题我两次都选的C，因为总觉得应该跟前面对称，尽管意思上知道是在比速度问题...

对称到底是以什么为对称的标准呢？

...难道是这个题找的不合适...

那换一道题好了og12

85. Salt deposits and moisture threaten to destroy the
Mohenjo-Daro excavation in Pakistan, the site of an
ancient civilization that flourished at the same time
as the civilizations in the Nile Delta and the river
valleys of the Tigris and Euphrates.
(A) that flourished at the same time as the
civilizations---正解
(B) that had flourished at the same time as had
the civilizations
(C) that flourished at the same time those had
(D) flourishing at the same time as those did
(E) flourishing at the same time as those were

其实这道题我总觉得应该是that flourished at the same time as the civilizations did

因为应该是两者flourished的时间相比较嘛，总之就是这个类型的问题总是搞不懂

上面那道 省略了did