Answer:
Becuase in canada here it snows and yeah.
Explanation:
Littering, hunting specific endangered species, honestly there are tons of things so the easiest one would be littering because if animals eat certain things it can kill them.
Answer:
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.