Ответы и объяснения

1. you shouldn't be so serious all the time. you ought to join a club of smth
2. You shouldn't spend so much on CDs. You ought to save some money.
3. You shouldn't try to do so much. You ought to focus on one sport.
4. You shouldn't wash it so often. You ought to leave it for a few days between washes
1. don't have to
2. shouldn't
3. have to
4. ought to
5. mustn't
6. mustn't
1. have to apply
2. don't have to learn
3. Do your brother have to do military service?
4. have to get