Fact 1: Treating water is used to remove harmful substances before drinking.

Fact 2: Pollution is the release of harmful substances into the environment.

Given the two facts above, answer the question "what does treating water remove before drinking?" with the following options: 
- temperature
 - a pathogens
 - bacteria
 - h2o
 - mussels
 - oxygen
 - pollution
 - toxins


 

       pollution  