NotonlydidtheGreatWallofChinaserveasadefenseinthenorthb...

问题详情：

Not only did the Great Wall of China serve as a defense in the north but also______ the power of the emperor. 

A. symbolize             B. to symbolize            C. symbolizing              D. symbolized

【回答】

D

知识点：动词时态与语态

题型：选择题