Answer:
The alveoli are sacks coated on their inner wall by white and sticky liquid, they can be more than a millimeter in diameter and surface active agent. In them there is the exchange of gases between O2 and CO2.
They are evaginations of the epithelium of the air ducts with a single opening for the gases to exit and enter, controlled by the action of a smooth muscle sphincter. Its walls, called alveolar septa, provide a large increase in the exchange surface.
The answer is c because we just learned about it today. Viruses destroy cells
0.1 nanometer = 0.1 * 10^-9 meter = 10^-10 meter
Which you can see it's X-ray.
Glad to help you friend, not sure if you remember me or not :)
