Question

What are alveoli?

A. Tubes that connect the heart to the lungs
B. Air sacs used during respiration
c. Carbon dioxide molecules
D. Part of a red blood cell

Answer 1

Answer: B. Air sacs used during respiration.

Step-by-step explanation:

Answer 2

B

Step-by-step explanation:

Inside of your lungs, there are little pathways through which air flows, called bronchioles. Those bronchioles feed into tiny air sacs called alveoli, which fill with air when you breathe in and empty when you breathe out. Hope this helps!