Answer:
Remarkably efficient alveolar macrophages crawl freely along the internal and external alveolar surfaces
Explanation:
The alveolar macrophages are present on the internal lumenal surfaces of the alveolar ducts, the alveoli, and the bronchioles.
Alveolar macrophages are phagocytes that uses several surface receptors to release many secretions, to interact with other cells and molecules.
But the alveolar macrophages are intact to the inner surface only and do not crawl freely along the internal and external alveolar surfaces.
Hence, the correct option is " C".
This is false. There are many factors, like climate, fires, pollution, etc.
Cooling a substance causes molecules to slow down and get slightly closer together, occupying a smaller volume that results in an increase in density
