1. It's a good idea to go to bed early.
hoặc It is better if you go to bed early.
2. It's necessary to stay inside.
3. You would better study harder next semester.
4. You won't need to buy a new bike.
5. You should go away for a few days.
6. You should go to the doctor.
7. My parents should learn French words.
hoặc My parents should learn French words before going there.
9. Mai should not eat too much fatty food.
