题目内容：

Has it been announced ——?
A.when are the planes to take off
B.that are the plans to take off
C.where are the planes to take off
D.when the planes ate to take off

优质解答

答案应该是D,但是其中ate打错啦是are.这是一个主语从句,it 是形式主语,when the planes are to take off 才是真正的主语.切记:从句不用倒装,所以A,B,C都是倒装,所以是错误的选项.