`1` To stay healthy , you eat more vegetable and eat less high-fat food . 

`2` To prevent the flu , we eat a lot of garlic and keep our body especially feet warm .

`3` It began to rain , so I opened my umbrella .

`4` But he didn't  open his umbrella ( đề thiếu ) 

`5` He worked hard so he could earn much money . 

`6`  Study hard or you will fail the exam. 

`7`  Dan didn't study for the exam but Lan did .

`8`  -> I understand your point of view but I don't agree with it .     

-> I understand your point of view .However , I don't agree with it .     

____

And : và - dùng để thêm thông tin vào , nối thêm vế khác

But : nhưng - Dùng để nói về 2 vế trái ngược nhau 

Or : hoặc - dùng để giới thiệu một việc / cái  khác 

So : vì vậy - Dùng để nối 2 vế nguyên nhân kết quả và đứng sau dấu , 

However : tuy nhiên - Dùng để nối 2 vế trái ngược nhau .Đứng trước dấu . sau dấu , 

@ Dorris

1, To stay healthy, you eat more vegetables and less high-fat food.  ( and: và)

2,To prevent flu, we eat a lot of garlic and keep our bodies especially warm.

3, It began to rain, so I opened my umbrella. ( so : vì vậy , cho nên,..)

4, ( đề có vẻ thiếu đ ạ)

5, He worked hard so he could earn much money.

6,Study hard or you will fail the exam. ( or :hoặc )

7, Dan didn't study for the exam but Lan did.

8, I understand your point of view. However, I don't agree with it.  ( however : tuy nhiên)