What is the choices for the blank?
Homeostasis is maintained by the respiratory system in two ways: gas exchange and regulation of blood pH. Gas exchange is performed by the lungs by eliminating carbon dioxide, a waste product given off by cellular respiration.
Answer:
Si the hydrosphere
Explanation:
the hydroshhere is simply the total of all water
It detects that the small amount of virus added and it learns to fight off the flu which helps keep you from getting it