Ответ:

1. You mustn't drive on the pavement.

2. You shouldn't say that.

3. I don't have to go to work tomorrow.

4. I might buy this dress.

5. She must have gone out.

6. Steve can't have passed her exam.

7. You should eat more vegetables.

8. You must have be 18.

1 mustn't

2 shouldn't

3 don't have to

4 might

5 must

6 can't have

7 should

8 must have