GRAMMAR MODAL VERBS: MUST, SHOULD, Complete the sentences with MUST, MUSTN'T, SHOULD, SHOULDN'T, HAVETO or DON'THAVETO/DOESN'THAVETO. 1. study this weekend. It's my obligation as a student. 2. You feed the animals in the zoo. It's forbidden! 3. make my bed every morning. I help my parents at home. 4. You do exercise every day. It's good for you. 5. You listen to loud music. It's bad for your ears! 6. You help me now. Dad helped me this morning. 7. They study harder if they want to pass their exams. 8. You use your mobile phone in class. 9. She wear a uniform at school. She can wear jeans. 10. You eat fast food. It's bad for you! merit Finish!!