Question

what occurs in the alveoli?
air is moved into the blood vessels while blood is moved into the alveoli.
carbon dioxide is moved into the blood vessels while oxygen is moved into the alveoli.
oxygen is moved into the blood vessels while carbon dioxide is moved into the alveoli.
blood is moved into the blood vessels while air is moved into the alveoli.

Explanation:

In alveoli, gas - exchange occurs. Oxygen diffuses from alveoli into blood vessels, and carbon dioxide diffuses from blood vessels into alveoli.

Answer:

Oxygen is moved into the blood vessels while carbon dioxide is moved into the alveoli.