The aveolus is surrounded by capillaries. So capillaries carry deoxygenated blood to the alveolus where the oxygen from the alveolus diffuses into the blood in the capillaries. The deoxygenated blood is now oxygenated and is carried out of the lung via capillaries that then merge into the pulmonary vein.
In other words, alveolus does not have oxygenated blood it just puts oxygen into the deoxygenated blood hat this brought in.
The discovery of DNA has allowed us to trace ancestors and find out how early humans lived, what they looked like, and who they were.
Answer: C
Explanation: All of them could be correct, but I think this is the correct answer. I’m only in middle school, so if your not rushing you may as well wait for someone else.