1 . In science, facts should be proved by experiments and research, and we ______ always believe everything we read and hear -- even if it is a great story.

A．can not

B．may not

C．must not

D．should not

2 . Hiking trips ________ sound exciting to most kids, but few realize they ________ be uncomfortable and even dangerous.

A．would; should

B．must; should

C．may; can

D．can; will

3 . —Tony, is that Mr. Black over there?
—I knew that he had gone to England. It          be him.

A．might

B．could

C．can’t

D．must

4 . I asked in the bookshop about Will Dutton’s latest book, but all they           tell me was that it would come out before the end of the year.

A．might

B．must

C．could

D．should

5 . —I heard our boss suffered great loss because someone had leaked information to our competitor.
—___________ that betrayed us? He was the first to be fired.

A．Must it be Sam	B．Can he be Sam
C．Can it have been Sam	D．Could he have been Sam

6 . Old age _______ burn and rage at the close of day; rage, rage against the dying of the light.

A．couldn’t

B．should

C．wouldn’t

D．shall

7 . —He ______be in the classroom. I think.
—No, he ______ be in the classroom. I saw him go home a minute ago.

A．can; may not

B．must; may not

C．may; can’t

D．may; mustn’t

8 . If someone happens to have high fever and pneumonia, he or she _________ seek treatment fast.

A．must

B．needs

C．may

D．could

9 . With no gravity to push against, astronauts’ bones and muscles ________become weak.

A．should

B．must

C．can

D．need

10 . —Everyone in my class passed the exam.
—Oh, really? It ________ difficult.

A．can’t have been	B．needn’t have been
C．must be	D．mightn’t be