1.It’s good for you to drink 2 litres of water every day.
⇒ You should drink 2 litres of water every day.

2.It’s good for you to bring a flashlight so you can see at night.
⇒ You should bring a flashlight so you can see at night.

3.It’s not good for you to drink soda every day.
⇒ You shouldn't drink soda every day.

4.It’s not good for you to go out at night.
⇒ You shouldn't go out at night.

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`+`It’s good for you to + V=You should + V.

`+`It’s not good for you to + V=You shouldn’t + V.