Your brain sends signals to your body to release hormones that make you tired. This is done as a routine, and trying to sleep at different times will mess it up.
Hope this helps!
Natural selection could not occur without environment, and a act on animal.
Answer:
I'm pretty sure it's 2n correct me if I'm wrong
Explanation:
I'm not to smart with this kind of stuff.
Mutualism because both animals benefit. The Elephant gets relived from the parasites that are on it and the bird gets food.
B
A convergent boundary is an earth where two or more lithospheric plates collide