in the queue for 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
网友回答
A. To wait
B. Have waited
(答案→)C. Having waited
D. To have waited
解析：考查非谓语动词。句意：已经在队列里等了一个小时，汤姆突然意识到他把钱包忘在家里了。现在分词表示正在进行的伴随性的动作，其逻辑主语是句子的主语，如果分词动作发生在主语动作之前，则要用完成时态的现在分词，故选C。