The mayor of the city says that all construction work for the stadium ______ by 2015.

问题描述:

The mayor of the city says that all construction work for the stadium ______ by 2015.
A.will be completed
B.will have been completed

将来完成时态 有很明显的暗示 2015年 这是未来的一个时间
by + 未来的时间 是将来完成时态的标志