Fact 1: Gases from burning coal and oil dissolving in water in the atmosphere causes acid rain.

Fact 2: Coal-fired power plants contribute to acid rain.

Given the two facts above, answer the question "what can power plants cause?" with the following options: 
- Pesticides
 - wind
 - heat energy
 - acid rain
 - friction
 - Pollution
 - coal
 - oil


 

    acid rain     