1.As a doctor,you try your best to cure your patients.
答案should/ought to/must
2.In some parts of the world,you boil the water before drinking it.
答案must/have to
3.He have stayed at home this morning.I saw him shopping in another city.
答案can’t/couldn’t
4.You smoke in this part of the hospital.
答案mustn’t
5.—You have finished the article.The deadline is last Friday.
—Sorry.I have been busy these days.Could you give me three days more?
答案ought to/should
6.He have caught a bad cold last night,for his forehead felt burning.
答案must
