`I)`

`1` . Vitamin plays an important role in our diet.

`->` Play (an) important role(s) : đóng vai trò quan trọng

`2` . We should keep our bodies warm to avoid catching a flu or a cold.

`->` Should + Vinf : nên làm gì / avoid + Ving : tránh việc gì

`3` . Getting enough rest (will help you/helps you) concentrate at school.

`->` Help sb/sth do sth : Giúp ai đó/cái gì làm việc gì đó.

1. Vitamin plays an important role in our diet. (play an important role: đóng một vai trò quan trọng)

2. We should keep our bodies warm to avoid catching a flu or a cold. (should + V(bare))

3. Getting enough rest helps you concentrate at school. (help sb do sth: giúp ai đó làm gì)