问题
选择题
_____in the queue for half an hour, Tom suddenly realized that he had left his wallet at home. [ ]
A. Waiting
B. Have waited
C. Having waited
D. Waited
答案
答案:C
_____in the queue for half an hour, Tom suddenly realized that he had left his wallet at home. [ ]
A. Waiting
B. Have waited
C. Having waited
D. Waited
答案:C