Answer: a change in the temperature of the materials
Explanation:
The process responsible for this is mass movement.
Semi permeable membrane will allow something to pass through them and something not and it will allow on the basis of size particles
while differentialy permeable will include other factors also other than size and will depend on the need of the cell
this is the main difference between them
hope it helps<span />
Cold air usually pushes warm air because cold air has a HIGHER DENSITY
I'm not entirely sure what you mean, but a fit animal is one that is able to out-compete with other animals in its ecosystem. It possesses some kind of advantage, which makes it easier to compete with others for food, water, shelter, and mates. Due to these qualities, the animal is obviously able to live for a good deal of time and have a greater chance of producing viable offspring.