Question

all the windows have closed

I would not leave the room until I___all the windows.A. closed B.have closed C.would have closed
D.had closed 为什么选D?

Answer 1

D.had closed 过去完成时 close 发生在 leave 之前 !
leave是过去动作（would not leave ） 所以 close 发生在过去的过去 即 过去完成时

请给满意 谢谢!