______ in the hall for half an hour, the old man suddenly realized he had left the wallet in the car.
A. Having waited
B. Wait
C. To wait
D. Being waited
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______ all the letters, I went outand had a drink.
A. Finish
B. Having finished
C. To finish
D. Finishing
While ______ a tunnel through the mountain, the workers discovered an underground lake.
A. built
B. to built
C. being built
D. building
Do you know the girl ______ by the window?
A. sits
B. to sit
C. sitting
D. sat
The police searched the area and finally found the ______ boy.
A. missing
B. missed
C. to miss
D. miss
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