You are presented with the question "What removes harmful substances from water before drinking?" and the following answer choices: 
- Calcium carbonate
 - evaporation
 - circulatory systems
 - sugar
 - chlorine bleach
 - one celled organisms
 - glass
 - cyanide

Now knowing that treating water is used to remove harmful substances before drinking and chlorine bleach is ideal for treating water, choose the best answer.


 

     chlorine bleach    