1.  No.1, I live by a factory, it cause a lot of dity smoke every day, so I fell hard to breath .

2.  In many countries, even the fresh water used to eat can't be ensured , which has caused a lot of trouble in people's everyday life, why ?

3.  In addition, people cause a lot of pollutions , which demage the source of fresh water.

4.  will cause a lot of problems.

5.  Too many activites , on the other hand, will cause a lot of problems.

6.  That would cause lots of problems.

7.  Too much activities on the other hand, will cause a lot of problems.

8.  Too much activities, on the other hand, will cause a lot of problems.

9.  Too much activities, on the other hand, will cause a lot of problems.

10.  Taix also cause a lot of problems.