True, air mass is a part of atmosphere. This is also a geography/geology question, not a bio question.
Thicker Skin, Fur, More Fat Content
Gas transport is the movement of O₂ and CO₂ between the systemic capillary beds and the pulmonary capillary beds.
<span>An element is a pure substance that cannot be broken down into anything simpler by physical or chemical means.</span>
