The allow oxygen and carbon dioxide to be exchanged between the lungs. These structures resemble a bunch of grapes.

A•Alveoli
B•Bronchioles
C•Sinuses
D•Cilia

Alveoli
Alveoli are the little sacs at the end of the bronchioles (Figure below). They look like little bunches of grapes. Oxygen is exchanged for carbon dioxide in the alveoli. That means oxygen enters the blood, and carbon dioxide moves out of the blood.

label and order

Explanation:

I remember my teacher saying that they had to be labeled and in order so that accidents dont happen. we dont need kids drinking windex because it wasn't labeled and it was near the cafeteria, not in the storage room. if you label and order them then they are already stored and dont have to be located