After by the police for several days the robber had to give in. A. surroundingB. surround

问题补充：

After by the police for several days, the robber had to give in.

A. surrounding

B. surrounded

C. surround

D. being surrounded

答案：

A. surrounding

B. surrounded

C. surround

(答案→)D. being surrounded

解析：考察非谓语动词，after 是介词，后面的动词要用doing形式，后面的主语the robber与surround之间是被动关系，所以选择D

句意为，在被警察包围了几天之后，那个强盗最终屈服了