31.By the time we the airport, the plane .
A. arrived at; had taken off
B. had got to; took off
C. got to; had taken away
D. arrived at ; had taken away
网友回答
(答案→)A. arrived at; had taken off
B. had got to; took off
C. got to; had taken away
D. arrived at ; had taken away
解析：考查时态。By the time主句用完成时态。根据句意我们到达机场的时候，飞机已经起飞了。可知从句用一般过去时，主句用过去完成时，选A。