Fact 1: Amold spore has a negative impact on the respiratory system.

Fact 2: Another name for the breathing tree is the respiratory system.

Given the two facts above, answer the question "What do mold spores make it hard to do?" with the following options: 
- clean house
 - motility
 - kill them
 - breathe
 - reproduce
 - eat bread
 - play outside
 - survive


 

    breathe     