Salt deposits and moisture threaten to destroy the Mohejno-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 正确答案是A,我选的是B. 先不说应该是过去完成时还是过去时,但是A的as 后面不应该接did the civilizations么?我现在有点糊涂到底什么时候需要加助动词什么时候不需要加? 多谢指教! |