`A.`

`1.` True 

`@` D/c: Thirdly, we should cat food that is good for our teeth and our body such as milk, cheese, fish, potatoes, rod rice, raw vegetables and fresh fruit.

`2.` False

`@` D/c : Secondly, we should brush our teeth at least twice a day once after breakfast and once before we go to bed.

`B.` 

`1`. twice a year 

`@` D/c: First, we should visit our dentist twice a year.

`2.` He exams our teeth and fill the small holes in our teeth before they destroy the teeth.

`@` D/c: He can exam our teeth and fill the small holes in our teeth before they destroy the teeth.

`3.` Yes, it is.

`@` D/c: Chocolate, sweets, biscuits and cakes are harmful because they stick to our teeth and cause decay.

`A)` 

`1` T

`->` Dòng 4 , đầu dòng 5 : "Thirdly , we shoud eat .... fresh food"

`2` F

`->` Cuối dòng 2 , đầu dòng 3 : "Secondly , we should ..... go to bed "

`->` "at least twice a day" chứ không phải "at least twice a week"

`B)`

`1.` twice a year 

`->` Câu 2 , dòng 1 : " First , we should visit our dentist twice a year"

`2.` He exams our teeth and fill the small holes in our teeth before they destroy the teeth

`->` Cuối dòng 1 , đầu dòng 2 : " He can exam ..... the teeth"

`3.` Yes

`->` Cuối dòng 5 , dòng 6 : "Chocolate , ...... cause decay"

$baoyen.$