6. I must/have to submit my homework before 12 o'clock because the deadline is 12 o'clock.
7. I must/have to stay at home to take care of my children.
8. My friend says: "You don'thave to/mustn't drink champagne. You can have a coke or fruit juice instead.
9. You don't have to/mustn't drink if you're going to drive afterwards.
10. You don't have to/mustn't pick up Tom at the airport because Judy will pick him up.
6 must
7 have to
8 don't have to
9 mustn't
10 don't have to