Question

______ in the queue for half an hour,Tom suddenly realized that he had left his wallet at home.

A.To wait                                   B.Have waited

C.Having waited                  D.To have waited

Answer 1

C

解析:

本题考查非谓语动词作时间状语。根据语境wait的动作发生在realized之前，所以用完成式。动词不定式常作目的状语。选项B很显然是错误的，它不是非谓语动词。