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
