The best and most correct answer among the choices provided by your question is the second choice or letter B.
Reptiles don't sit on their eggs like birds do because r<span>eptile eggs are not amniotic and have no shell, so sitting on them would crush them.</span>
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Answer:
DIFFUSION
Explanation:
Water, carbon dioxide, and oxygen are among the few simple molecules that can cross the cell membrane by diffusion (or a type of diffusion known as osmosis ). Diffusion is one principle method of movement of substances within cells, as well as the method for essential small molecules to cross the cell membrane.