You are presented with the question "Distilling water removes what before people drink it?" and the following answer choices: 
- one celled organisms
 - single-celled organisms
 - layers of fat
 - Chemical energy
 - harmful substances
 - hydrogen
 - water
 - oxygen

Now knowing that treating water is used to remove harmful substances before drinking and distilled water is treated to remove the minerals found naturally in the water, choose the best answer.


 

     harmful substances    