That flow in all directions!!!
I think it’s a forelimb of a whale
Answer:D
Explanation: The pulmonary air sacs of birds only permit a unidirectional flow of air through the lungs. Unidirectional flow means that air is inhale and exhale through one trachea alternatively. This means the bird lungs only receive largely fresh air which has a high oxygen content during inhalation and do not receive fresh during exhalation. While air flow bidirectional in mammals.
Answer:
it is (A)
Explanation:
i did this like a mouth ago
Neither of these are minerals, B.
Its not A because, they are not natural materials but instead made up of natural materials, like a rubber tree.
Its not C because, like I said, plastic is made from rubber trees, this garentees it doesnt have a crystal structure.
Its not D because, concrete is not a mineral and has indefinite composition.
