1.

These days, a lot of endangered animals by hunters and poachers. The best way to stop them is more police to arrest them.

2.

Underground water by agricultural sprays. The best way to deal with the problem is safe agricultural sprays.

3.

During the past few years, lots of trees by acid rain. One thing to do about it is factories that pollute the air.

4.

Prices a lot in recent years in Argentina. One way to deal with inflation is to buy a company's products.