He________sleep，although he tried to，when he got on such a hunt for an idea until he had caught it.
#62298
A
wouldn’t
B
shouldn’t
C
couldn’t
D
mustn’t
推荐题目
--Listen! Tom is singing in the next room.--It _______ be Tom. He has gone to Shanghai.
#74959
A
may
B
must
C
mustn’t
D
can’t
One of our rules is that every student wear the school uniform while at school.
#62622
A
might
B
could
C
shall
D
will
— I want to know if I smoke here.— No, you . Could you see the sign “NO SMOKING” there?
#63025
A
can; needn’t
B
must; can’t
C
shall; won’t
D
may; mustn’t