Mary was caught in a traffic jam and by the time she arrived at the airport her father’s plane .
A. took off
B. had already taken off
C. was take off
D. had already been taken off
网友回答
A. took off
(答案→)B. had already taken off
C. was take off
D. had already been taken off
解析：by the time与she arrived这一过去的动作连用，表示到过去那时为止已经完成的动作，用过去完成时。take off指“起飞”，没有被动语态。