27) The construction of the laboratory ____by the end of nex
5个回答

The construction of the laboratory _B___by the end of next month.

A) must be completed

B) must have been completed

C) will be completing

D) will have been completing

----"by end of +将来时间",动词用“将来完成时”,又由于The construction of the laboratory(实验室的建设)不会自己完成,应用被动语态,所以排除D,只能选完成时被动语态的B.