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

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

To wait

Have waited

Having waited

To have waited

试题答案

答案：C

分词作状语。wait和逻辑主语Tom之间是主谓关系，要用现在分词waiting。“已经等了半个小时了才想起来……”，因此用完成式。