题目内容：

I arrive at the airport ——the plane had taken off.
A:after
B:while
C:when
D:before

优质解答

这句子有点奇怪,这样比较正常：
When I arrived at the airport,the plane had taken off.-我到机场时飞机已经飞走了.
从句过去,主句发生在从句之前,过去完成.B!
此答案建立在LZ打错o题目出错的基础上...