Fact 1: The emission of sulfur dioxide causes acid rain.

Fact 2: Scrubbers significantly reduce emissions of sulfur dioxide.

Given the two facts above, answer the question "Scrubbers can be used for what?" with the following options: 
- Animal survival
 - storing water
 - hydrate their cells
 - water conservation
 - reducing acid rain
 - Relieve pain
 - root growth
 - protect them


 

     reducing acid rain    