Question

Mary was caught in a traffic jam and by the time she arrived at the airport her father’s plane______.

1. A.
   took off
2. B.
   had already taken off
3. C.
   was take off
4. D.
   had already been taken off

Answer 1

B
by the time與she arrived這一過去的動作連用，表示到過去那時為止已經完成的動作，用過去完成時。take off指“起飛”，沒有被動語態。