Question

Helen ______ her keys in the office so she had to wait until her husband ______ home.

   A. has left; comes                    B. left; had come

   C. had left; came                     D. had left; would come

 

Answer 1

【答案】

C

【解析】考察时态。根据句意可知，Helen因为先把钥匙丢在了办公室，所以她要等她的丈夫回家。

所以leave发生在had to wait之前，即过去的过去，用过去完成时，第二空是until引导的时间状语从句，从句中用一般过去时表示过去将来。