What harms the respiration system?
Pollution sweating Pesticides exercise smoking parasites swimming breathing
A B C D E F G H
Mammals are warm blooded, use lungs for respiration, and have four legs.
Smoking causes damage when respirating.
What harms the respiration system? (A) Pollution (B) sweating (C) Pesticides (D) exercise (E) smoking (F) parasites (G) swimming (H) breathing