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.

My question is why there is no verb in as clause. as + S ( S = subjective ) ; as + S + V ( S = objective ) in this situation, should there be any verb? thanks!

1.the same...as...

2.an ancient civilization 与 the civilization 比较,无动作发出者.

我认为, as introduces a clause, 省略了V.,补全的话是：

...an ancient civilization that flourished at the same time as the civilizations flourished in the...

 情况类似于：

His wife had a baby at the same time as Elaine. (from Longman dictionary of contempory English)

75. 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

(D)           flourishing at the same time as those did

(E)            flourishing at the same time as those were

我把粘下来，再次提问，

问题一同LZ为什么此处的AS后面不是句子，因为第76句的解释就说   a clause must follow as to complete the sentence。lvqingling的解释明白了。

问题二，这里D和E选项中的those不对吗？解释中说those 应该是指代an ancient civilization 我怎么觉得是指代the civilizations 。

麻烦nn了

those 是复数指代，而前面没有对应的复数名词可指代（语法上可以勉强说有，逻辑上无），故补出名词

并且与 in the Nile delta and the river valleys of the Tigris and Euphrates 的修饰对称

如果这样的话，flourished可以省略吗？我觉得应该补上did才对啊。
不补did的话，像一些人说的，是an ancient civilization和 the civilizations比，我觉得这种说法不对，比较的对象是 an ancient civilization flourished 和 the civilizations flourished的时间，因为有same time所以才有可比性。

比如想个简单的句子。 Mike went to school at the same year as David  did.
这句话 应该是不可以省略成：  Mike went to school at the same year as David 吧？

如果把B选项改为：that had flourished at the same time as the civilizations had ,理解为过去一度flourished，改完的选项能选吗？