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

1. A.
   To wait
2. B.
   Have waited
3. C.
   Having waited
4. D.
   To have waited

______ 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?

______ 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

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

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

A. To wait          B. Having waited     C. Have waited   D. To have waited