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

A) Gases to pass through their walls easily

Explanation:

Alveoli have walls that are very thin, and this allows carbon dioxide and oxygen to pass between the alveoli and small blood vessels called capillaries.

nucleic acid molecules are incredibly complex, containing the code that guarantees the four different nucleotide units comprise dna, the nucleic acid of interest to the genealogist. and one of four nitrogen-containing molecules called nucleotides