By the end of next year they the work on the new stadium.A. would have completedB. had co

问题补充：

By the end of next year，they the work on the new stadium.

A. would have completed

B. had completed

C. will have completed

D. have completed

答案：

A. would have completed

B. had completed

(答案→)C. will have completed

D. have completed

解析：

考查时态。根据时间状语“By the end of next year”可知，本句应使用将来完成时态，表示到明年年底前他们将已经完成新体育馆的建设。