--Who has opened the door?  ---I think it __ be Lin Tao. He’s always the first to get here.
#88947
A
is able to
B
can't
C
must
D
mustn’t
推荐题目
We ________ jump to conclusions before we have all the facts.
#86585
A
couldn't
B
mightn't
C
shouldn't
D
mustn't
How happy we _______, if you had come with us to the party. 
#89782
A
could be
B
may have been
C
would have been
D
were
The petrol tank is empty. I _________it up before we left home.
#86645
A
had to fill
B
would have filled
C
should have filled
D
could have filled