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

网友回答

A. To wait
(答案→)B. Having waited
C. Have waited
D. To have waited
解析：
试题解析：考查考查非谓语动词做状语。动词与逻辑意义的主语是主动关系，同时动作发生在主句之前，所以用分词的完成时。句意： Tom 排队等了半个小时后，他突然意识到把钱包落家里了。