Question

Difference of breathing through mouth and nose

Answer 1

Because the nostrils are smaller than the mouth, air exhaled through thenose creates a back flow of air (and oxygen) into the lungs. And because we exhale more slowly through thenose than we do though the mouth, the lungs have more time to extract oxygen from the air we've already taken in.

Answer 2

the nostrils r smaller than mouth so air exhaled through the nose creates a back flow of oxygen in the lung.and we exhale more slowly through the nose than we do through our mouth.