I’ve come to ask him for the book. That’s why I （） wait until he comes back.

A.Should
B.Will
C.Shall
D.Are

A.need    to
B.don’t    need
C.needn’t
D.need

A.it   must   have  rained
B.it   must   rain
C.it   must   be    raining
D.it   must   have   been  raining