请教OG 80

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
(B) that had flourished at the same time as had the civilizations
(C) that flourished at the same time those had B
(D) flourishing at the same time as those did
(E) flourishing at the same time as those were

D and E also incorrectly use the present participle flourishing where that flourished is needed.

My question is that why "flourishing" can't be the simple form of "that flourished"?

For example: The guy that runs so fast is my friend. ==> The guy running so fast is my friend.

Thanks.

Present participle should be used when you want to talk about something that is happening at the time of speaking.

The guy running so fast is my friend is correct only if your friend is still running at the time of your speaking. If the guy has stopped running, nobody will have a clue whom you are talking about. Then you probably want to say, "The guy who ran so fast is my friend."

I consider "flourishing" a reduced clause( or a nonfinite clause), not a present participle.

General speaking, when you want to reduce a relative cluase, first remove S, then change

the verb to Ving. I just don't get why in this example "that flourished" can't be reduced to

"flourishing".

Here is another example.

Her brother that lived in U.S last year visited us this morning.

==> Her brother living in U.S last year visited us this morning.

as .. as应该要求两边对称的把，前面用进行时态后面用过去时有问题

I don't really understand.

There is no "as ...as" structure in the question. It's the "the same time as".

Actually, I understand that in D&E, "those" is illegal.

I just want to know why "flourishing" can't be used here".

Thanks.

顶 同样疑惑中

为什么不能理解成 当时正繁荣的文化 这样不是应该用ing 形式了吗？

想了半天 觉得此处 that flourished is needed 是因为限定性定语从句与非限定性范围的差异

an ancient civilization 特指那个时期