The alveoli are tiny air sacs in the lung. They have a relatively large surface area and thin walls. This structure allows-
A) gases to pass through their walls easily
B) blood from the capillaries to be absorbed easily
C) the absorption of moisture from air in the lungs
D) the storage of as much carbon dioxide as possible
Alveoli have walls thatare very thin, and this allows carbon dioxide and oxygen to pass between the alveoli and small blood vessels called capillaries.
