7. There are outbreaks of cholera because people drink untreated water. ( Rewrite, using “because of”) 
=> because of drinking untreated water ( nước chưa qua xử lí), there are outbreak( sự bùng phát ) of cholera ( dịch tả) 
8. There was acid rain in this area. The trees were damaged. (Rewrite, using “caused”)
- the acid rain in this area caused damage to the trees
9. There was acid rain in this area. The trees were damaged. (Rewrite, using “made”)

=> the acid rain in this area made the trees damage
10. People get sick so often because they don’t exercises regularly. 
( Rewrite, using “If”)
- If people did exercise regulary, they wouldn’t get sick so often.

7. There are an outbreak of cholera because of the untreated water.

8. The acid rain in this area caused damage to the trees.

9. The acid rain in this area made the trees damage.

10. If people did exercise regularly, they wouldn’t get sick so often.