VI. Cross out the wrong part in the following sentences. 1. You don't have to/ must eat anything you don't like. 2. If you don't want to have a sore throat, you don't have to/ oughtn't to drink too much iced water. 3. Flight attendants have to/ mustn't take care of passengers on the plane. 4. During the lesson, students don't have to/ mustn't leave class without the teacher's permission. 5. Her mother cooks for her, so she herself doesn't have to/mustn't cook. 6. Smokers don't have to/ mustn't smoke in public places. This is stated in a new law. 7. Drinks are free for today. It means that you don't have to/mustn't pay money for drinks today. 8. Kelvin won the lottery last year, so he doesn't have to/mustn't work now. 9. According to the company regulations, staff have to/ must finish their work with highest efficiency. 10. To be healthy, we mustn't/ ought to eat healthful food and do the exercise regularly.

1 don't have to

2 oughtn't to

3 have to

4 mustn't

5 doesn't have to

6 mustn't

7 don't have to 

8 doesn't have to

9 have to

10 ought to