—Who’s that boy reading in the study ? Is it David?—It __________ be David. I saw him go home just now.
#74950
A
must
B
can’t
C
may
D
shouldn’t
推荐题目
Students ought ______ the truth.
#76163
A
told
B
tell
C
telling
D
to tell
Tom ____his homework yesterday, because he was in hospital all day.
#63327
A
can’t finish
B
couldn’t finish
C
couldn’t have finished
D
mustn’t finish
—I called you at 9 last night,but no one answered.—Sorry,I ________ sleeping.I went to bed very early. 
#62284
A
need have been
B
would have been
C
must have been
D
should have been