Q: Fact 1: Abreathing mask is used for keeping harmful particles from entering the respiratory system. Fact 2: When inhaled, the particles lodge in the respiratory system, causing or aggravating health problems. Given the two facts above, a breathing mask keeps what from being inhaled and causing health problems?

OPT:
A). cigarettes
B). harmful particles
C). chemical changes
D). influenza
E). oxygen particles
F). hydrogen and oxygen
G). air particles
H). atmosphere particles
A:
B).