Answer:
When you inhale (breathe in).
Explanation:
Air enters your lungs and oxygen from the air moves from your lungs to your blood. At the same time, carbon dioxide, a waste gas, moves from your blood to the lungs and is exhaled (breathe out). This process is called gas exchange and is essential to life.
My answer would be radiation.
I think the first one, species must have descended from preexisting species.
Answer:
I think the answer would be C
Explanation:
Btw don't be afraid to correct me if i'm wrong :) And don't worry about putting me as brainiest
Answer:
Answers may vary, but in simple terms:
a) The ability of an organism to maintain its internal environment, despite changes to its internal or external environment.
b) The excretory system maintains homeostasis by controlling the amount of water, ions, and other substances found within the blood.
c) By simply controlling and regulating the other parts of the body.