MUST/ HAVETO - MUSN'T/ DON'T HAVE TO - OUGHT TO/ OUGHT NOT TO

Students ____ go to school on Sundays; there is no class then.

• must

• have to

• don't have to

• mustn't

This is a closed-book exam, so you ____ use any reference books in the examination room.

• must

• have to

• don't have to

• mustn't

The project work in this semester is optional, so students ____ do it.

• must

• have to

• don't have to

• mustn't

Her husband has become a millionaire. She ______ work hard now.

• mustn’t

• doesn’t have to 

• shouldn’t

• can’t

We _____ reveal our customers’ information to any third party. That’s the rule.

• mustn’t

• don’t have to

• shouldn’t

• can’t

This drink isn't beneficial for health. You ____ drink it too much.

• should

• ought to not

• ought not to

• mustn't

This warning sign indicates that you ____ step on the grass.

• shouldn't  

• mustn't

• don't have to

• ought not to

Hoa ____ feed the cats because her mother has done it already.

• has to

• doesn't have to

• must 

• Both A and C

Water park is free for kids under 6 years old, so you ____ pay money for your son.

• have to

• mustn't  

• should

• don't have to

You ____ tell anyone what I've revealed to you. It's still a secret.

• mustn't

• had better not

• ought not to

• don't have to