`A`

`21.``F`

→ Dẫn chứng: We ought to visit our dentist twice a year

`22.` `T` 

→ Dẫn chứng: we should brush our teeth with a toothbrush and fluoride toothpaste at least twice a day  

`23.` `T` 

- Dẫn chứng : dòng cuối đoạn 2

`24.` `F` 

- Dẫn chứng: Chocolates, sweets, biscuits, and cakes are bad 

`B` 

`25.` `D` 

- We ought to visit our dentist twice a year

`26.` `C` 

- đoạn 3 dòng 1+2

`A.`Answer True or False

`21.T`

`=>`Dẫn chứng : Firstly, we ought to visit our dentist twice a year. ( Câu 1 dòng 1 của bài )

`22.T`

`=>`Dẫn chứng : Secondly, we should brush our teeth with a toothbrush and fluoride toothpaste at least twice a day - once after breakfast and once before we go to bed. ( Đoạn văn số 2 của bài )

`23.T`

`=>`Dẫn chứng :  We can also use wooden toothpicks to clean between our teeth after a meal. ( Câu 2 đoạn 2 )

`24.F`

`=>`Dẫn chứng : Chocolate, sweets, biscuits and cakes are bad, especially when we eat them between meals. They are harmful because they stick to our teeth and cause decay. ( 2 câu cuối của bài )

`B.`Choose the best word or phrase (A, B, C, or D)

`25.D`

`=>`Dẫn chứng : Firstly, we ought to visit our dentist twice a year. ( Câu 1 dòng 1 của bài )

`26.C`

`=>`Dẫn chứng : Thirdly, we should eat food that is good for our teeth and our body such as milk, cheese, fish, brown bread, potatoes, red rice, raw vegetables, and fresh fruit. ( Câu 1 đoạn 3 )