Modal verbs "must", "mustn't", "have to" or "don't have to"

Whatever you do, you ... touch that switch. It's very dangerous.

You ... forget what I told you. It's very important.

We ... to leave yet. We have got plenty of time.

Ann is feeling ill. She ... to leave the party early.

I ... to go to the bank to get some money.

The window are very dirty. I ... to clean them.

These cakes are very nice. You ... have one.

We ... take an umbrella. It's not going to rain.

You ... buy a newspaper. You can have mine.

The windows aren't dirty. You ... clean them.