ll,

`1.` We should keep our bodies warm to avoid flu and a cold.

`2.` You shouldn't play more computer games in your free time.

`3.` Vitamins play an important role in your diet.

`4.` Getting enough rest helps you concentrate on school.

`5.` The doctor is asking Huy some questions about his health problems.

`..........................................................................`

III,

`1.`with`→`for

`2. `in`→`of

`3.` on`→`from 

`4.` in`→`to

`5.` has`→`had 

1. we /keep/our bodies/warm/avoid/flu/a cold.

We should keep our bodies warm to avoid flu and a cold.

2. getting/enough/rest/help/you/concentrate/sclool.

Getting enough rest helps you concertrate on school.

3.vitamins/play/important/role/our diet.

Vitamins play an important role in our diet.

4.you/not/phay/more/computer games/free time.

You should not play more computer games in your free time.

5.dortor/asking/huy/questions/about/health problems.

The doctor is asking Huy some questions about hiis health problems.

II

1. Laughing is good with => for health.

2.Some people have a very bad habit in => of littering in public .

3.People who live in a dusty area often suffer on => from diseases.

4.  In => To prevent flu, we should keep our hands clean , our feet warm .

5. She has => had a sore throat yesterday .