Breathing begins with inhalation when the contraction of the diaphragm flattens on contraction, pulling the lungs down. The contraction of these muscles increases the volume of the lungs. This reduces the air pressure in the lung to below that of the external air. This pressure difference forces air to move into the lungs where gas exchange occurs. The relaxation of the diaphragm and intercostals reduces the volume of the lungs, which then increases the air pressure inside the lung to that above the external air. This forces air out of the lungs. The cycle goes on and on. Hope this helped!
Answer:
gas
Explanation:
According to National Geographic, "Stars are huge celestial bodies made mostly of hydrogen and helium that produce light and heat from the churning nuclear forges inside their cores." Which basically means they're big balls of gas
hope this helps:)
A lot. Sadly there are also a lot of Americans who believe that everything will just be handed to them. You must earn what you want.
Under the Indian construction law approved
