53. We _D_ our breakfast when an old man came to the door.

问题描述:

53. We _D_ our breakfast when an old man came to the door.
A just have had B have just had C just had D had just had
为什么不选B?

D对
因为主句的动作发生在从句之前,从句的时态是一般过去时,故从句要用过去完成时‘表示过去的过去已经发生或完成了的动作.