Using modal verbs ( must / have to / mustn't / need / needn't

You ... eat too many sweets.

You ... drive fast.

You ... apologise. It isn't necessary.

You ... smoke in here. Smoking is not allowed.

I ... be late. It's the most important meeting of the year.

You ... drive so fast. We have a lot of time.

I ... take the umbrella. It won't rain.

The students ...  forget their homework.

You ... put salt in her food; the doctor said she can't eat salt.

We .... cook more. There's enough food.

You ... eat and drink in the library.

You ... switch off your mobile phones during the lessons.