2.Use must mustn't, should shouldn't: 1. You must/ should/shouldn't be 18 before you can drive.
2. You mustn't/ shouldn't go to bed so late. It's not good for you.
3. You must/shouldwear a school upiform in most state schools.
4. You mustn't/shouldn't copy during exams.
5. You must/ should be very tall to play basketball.