Изменить предложения используя модальные глаголы may; must; can; need to; should.
11. If you want my advice, go to the dentist!
12. I'm sure they are at home. The lights are on.
13. If you don't stop eating so many cakes, you'll ha stomachache.
14. I'm sure she knows you are here.
15. They don't allow talking on the phone here, but most people do.
16. Maybe your friend will call you on your birthday.
17. He knows how to play golf.
18. It wasn't necessary for you to make your bed, they hotel staff would have done it.
19. It isn't necessary to do exercise 7.
20. Here's my advice: work harder.
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