The building of the lab ____ before the end of this term.

The building of the lab ____ before the end of this term.
The building of the lab ____ before the end of this term.
A.must have completed B.must have been completed
C.must be completed D.must complete
还有一题：
If you ____ quiet,I’ll tell you what happened.
A.are B.will be
C.are to be D.be