问题

Why didn’t Susan come to school? —I don’t know. She____ ill.
A:could be
B:may have been
C:might
D:must have been
B:may have been
C:might
D:must have been
正确答案是:
同类题型
Up to now,the family’s business ______good. I hope our good luck will continue.
ld are you, madam— Ifyou _______ know, I’m twice my son’sage.
You should be careful when _______.—Yes, I will. I’d like to know when________ to have a rest.
Are you going to take part in the speechcompetition — _____. It’s too good a chance tomiss.