$\text{1.}$  

It's very useful for Mary to learn English.

$\text{2.}$

It's very good for your health to do morning excerises regulary.

$\text{3.}$

It's so relaxing to play badminton after work.

$\text{4.}$

It's necessary to recycle plastic bottles to reduce pollution.

$\rightarrow$ Giải thích: Cấu trúc: It's + adj+ (for sb)+ to do sth

1. Learning English is very useful for Mary => It's very useful for May to learn English .

2. Doing morning exercises is very good for your health=> It's  very useful for Mary to learn English.

3. Playing badminton after work is so relaxing => It's so relaxing to play badminton after work.

4. Recycling plastic bottles is necessary to reduce pollution => It's  necessary to recycle plastic bottles to reduce pollution

Cấu trúc:It's + adj+ (for sb)+ to do sth.

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