Fact 1: Abreathing mask is used for keeping harmful particles from entering the respiratory system.

Fact 2: All smoke is harmful to the respiratory system.

Given the two facts above, answer the question "What keeps smoke out of the respiratory system?" with the following options: 
- Cooking
 - Masks
 - Glasses
 - skin
 - Gloves
 - Hats
 - Urea
 - oxygen


 

  Masks       