Answer:
The oxygen enters the bloodstream from the alveoli, which are tiny sacs in the lungs where gas exchange takes place. The transfer of oxygen into the blood is through simple diffusion. While oxygen moves from the capillaries and into body cells, carbon dioxide moves from the cells into the capillaries and starts with high concentration but fades to low concentration.
Explanation:
Answer:
Covering mouth while sneezing
Explanation:
It prevents germs going airborne and spreading to another person or surface.
The other answers are ways to get better from an illness or are just inefficient
