Answer:
All life respires, or breathes. Respiration in mammals is similar to respiration in other air-breathing animals. Respiration extracts oxygen from the air, which is then used by cells. Respiration also carries waste carbon dioxide away from the cells. Although respiration depends on other systems, like the circulatory system, to take oxygen and carbon dioxide to and from cells, the respiratory system has the primary responsibility of bringing oxygen in to a mammal's body and sending carbon dioxide into the atmosphere.
Explanation:
hope it helps
Answer is A. I kid chemistry a while back but I am pretty certain it is A.
A polar molecule has a positive and negative end because of electronegativity.
