Must, ought, need.
1. I a lot of money to buy what I want .
2. Children … study at school till 16.
3. A doctor … be more polite to the patients.
4. We … take passport to make cruise over the world.
5. You … look after your sister .
6. You .. eat fruits and vegetables to keep your fit.
7. I have a meeting today, I … be hurry it.