问题
选择题
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
答案
答案：A
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。