(单选题)

______ for half an hour, the boy realized that he had made a mistake about the meeting time.

A.Waiting

B.To wait

C.Having waited

D.To have waited

参考答案：C

参考解析：

考查现在分词作状语。句意：等了半小时后，男孩意识到他把开会时间弄错了。the boy realized that he had made a mistake about the meeting time是主句，现在分词作条件状语，而且句意中体现出了事情发生的先后顺序，所以要用having done的形式，所以选择Having waited。故选C。

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