1.They must have been here the day before yesterday,________?
A.mustn't they
B.wasn't they
C.mustn't have they
D.hadn't they
2.----Why do you make me do so/
--------I'm sorry that you______do such a thing.
A.would B.can
C.should D.may
3.I ________often go fishing when I lived in the countryside.
A.should
B.would
C.could
D.might
为什么