Abreathing mask is used for keeping harmful particles from entering the respiratory system, and when mold grows in the house, it can emit particles that travel through the air. Given these facts, what can keep mold from entering the respiratory system among the following options:
- vaccinations
 - layers of fat
 - deep breaths
 - sweating
 - a breathing mask
 - moisture
 - organic molecules
 - hydrogen and oxygen


 

     a breathing mask    