

Chuyển những câu sau đây sang phủ định và câu nghi vấn:
1. She must go to school
2. You have to study harder
3. He há to do the housework
4. You ought to go to the dentist
1. She must go to school
2. You have to study harder
3. He há to do the housework
4. You ought to go to the dentist