Which statements explain the gas exchange that happens at the alveoli? Check all that apply.
Carbon dioxide moves from the air in the alveoli to the blood.
Carbon dioxide moves from the blood to the air in the alveoli.
The capillaries that surround the alveoli exchange both carbon dioxide and oxygen.
The capillaries that surround the alveoli exchange only oxygen.
Oxygen is absorbed by the blood in the capillaries that surround the alveoli.
Oxygen is the air we breathe out when we exhale.

B. Carbon dioxide moves from the blood to the air in the alveoli.

C. The capillaries that surround the alveoli exchange both carbon dioxide and oxygen.

E. Oxygen is absorbed by the blood in the capillaries that surround the alveoli.

Explanation:

Alveoli are the small sacs that are present in the lungs. Main function of alveoli is to exchange gases i. e. oxygen and carbondioxide with the blood that is present in the capillaries of the lungs. Blood that comes from the cell has high concentration of carbondioxide so it is taken by the alveoli and the oxygen present in the alveoli is absorbed by the cell. About 480 millions of alveoli are present in human lungs.