1 . —_________I go with my friends to the harvest festival?
—No. you’d better not.

A．Must

B．May

C．Would

D．Need

2 . Both drivers and passengers         wear seat belts while their cars are running on the highway.

A．must

B．can

C．may

D．need

3 . In order to make our dreams come true, we _______ work hard.

A．must

B．can

C．need

D．may

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

A．must

B．needs

C．may

D．could

5 . Timmy, why        in the mud? I have already told you so many times not to!

A．must you sit

B．should you sit

C．will you sit

D．can you sit

6 . —Mom,_____I hang out with Susan now?
—No,you_____.It’s dangerous for two girls to be outside at night.

A．could;can’t

B．could;needn’t

C．should;can’t

D．must;couldn’t

7 . — Why don’t you enter the office? They are waiting for you.
— The door ________ open, no matter how hard I pushed.

A．won’t

B．can’t

C．mustn’t

D．needn’t

8 . 尽管条件极其艰苦，我们必须坚持下去，直到成功。
We must ________ ________ till success in spite of the extremely difficult conditions.

9 . If fish are jumping higher than usual or frogs are croaking more loudly, it________ rain.

A．must

B．may

C．shall

D．need

10 . The designer has tried every possible way to make the robot light, so you_______worry about its weight.

A．must

B．may

C．can't

D．needn't