Must/Should/(don't)have to/ought to
1. I .......... be there in time or I'll miss my flight.
2. My sister .............. hand in her driver's license.
3. They .............. help him clean up the mess. (advies)
4. Dad says you ............ finish your dinner.
5. We ..............go to school today. The school is closed.
6. He is going to an informal party so he ............... wear a suit and tie.