Fact 1: Acid rain has a negative impact on water quality.

Fact 2: Acid rain comes from polluted clouds.

Given the two facts above, answer the question "Something that comes from polluted what has a negative impact on water quality?" with the following options: 
- flooding
 - clouds
 - streams.
 - stars
 - coal
 - concepts
 - minds
 - tar


 

  clouds       