It took me a long time before I was able to fully appreciate what they __ for me.A.had doneB.didC.would doD.were doing寻详解

分类: 作业答案 • 2021-12-20 02:32:00

问题描述：

It took me a long time before I was able to fully appreciate what they __ for me.
A.had done
B.did
C.would do
D.were doing
寻详解

答

我是按照过去完成时规律，应该选择 A

答

A
此动作发生在was able to之前,即表示发生在过去的过去,用过去完成时