I/1. should

2.shouldn't

3.should

4.should

5.shouldn't

6.should

7.should

8.should

9.should

10.should

11.should

12.should

13.shouldn't

14.shouldn't

15.should/should

II/1.She should take rest in a bed

2.morning exercise is doing healthy for good

3.We should eat healthy food much

4.She shouldn't carry heavy things 

5.You should have a breakfast good

6. You shouldn't eat ice cream

III/1.feel

2.hot

3.headache

4.Game

5.take

6.make

Mk là xong rồi nha

I.

1. Lan had a headache, she should take a rest.

2. My friends usually have toothache, they shouldn't eat sweets.

3. My grandfather has a backache, he shouldn't carry heavy things.

4. It's too cool today, you should wear warm clothes.

5. Quan has a fever, he shouldn't go out.

6. You has a stomach ache, you should drink warm water.

7. Your teeth is not good, you should go to the dentist.

8. You shouldn't go to bed late, because it's not good for your health.

9. After school, you should play sport to relax.

10. You should brush your teeth twice a day.

11. When you don't feel well, you should go to the doctor now.

12. You should stay at home when it's rain heavily.

13. You shouldn't watch TV too much because you will have a headache.

14. You shouldn't eat too much fast food because it's fatty.

15. In the morning, you should do morning exercise and you should have breakfast.

II.

1. She should rest take in a bed.

2. Morning exercise is doing healthy for good.

3. We should eat much healthy food.

4. She shouldn't carry heavy things.

5. You should have a good breakfast.

6. You shouldn't eat ice cream.

III.

Yesterday, my school had a Sports Day, I and my friend enjoyed it very much. However, when we came back home, we didn't feel well. It was too hot and in the afternoon, it rained heavily. Phong is my friend, he had a headache because the music was too loud. Some of my friends had a backache because they played some games. I also had a fever, because the rainy makes me wet. I think I and my friends should take a rest.