1 . People liked O. Henry’s stories, because simple as the tales were, they ______ finish with a sudden change at the end, to the readers’ surprise.

A．could

B．would

C．might

D．must

2 . I advise you to stay away from Mary. Although she is usually easy-going, she ______be quite annoying sometimes.

A．can

B．need

C．must

D．should

3 . —The test is very important to us. Do you think so?
—Yes, so we ________ be too careful during the test.

A．mustn’t

B．daren’t

C．needn’t

D．can’t

4 . This road is narrow and the traffic on it is heavy, so sometimes it ______ be blocked.

A．should

B．shall

C．can

D．need

5 . My nephew William is still a puzzle to me—sometimes he is as quiet as a mouse, while he______be fairly active at other times.

A．should

B．need

C．must

D．can

6 . Generally speaking, it’s very hot in summer in my hometown, but at times it ______ be cool.

A．need

B．must

C．can

D．should

7 . —— Look at the man in pink over there! Is he John?
—— He ________ be John who is away on a business trip now.

A．shouldn’t

B．mustn’t

C．may not

D．can not

8 . It _________ be quite cold in the mountains at night, so you’d better take a thick coat.

A．would

B．need

C．dare

D．can

9 . 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

10 . His greatest skill is that he ______ cook a meal of four dishes and a soup in less than half an hour.

A．must

B．need

C．can

D．would