Theyovercameallthedifficultiesandcompletedtheprojecttw...

問題詳情：

 They overcame all the difficulties and completed the project two months ahead of time, ______ was something we had not expected.

      A. that                         B. which                      C. it                             D. what      

【回答】

B

知識點：定語從句

題型：選擇題