The answer to this question is Homeostasis <span />
Afferent nerve fibers carry signals from the somatic receptors to the posterior horn of the spinal cord or to the brainstem. So i beleive it is 4 but not too sure. Hope this helped a bit (:
The natural succession of a small farm pond will tend to make the pond more likely to freeze solid in winter time,the nature of things helps them to merge more quickly and adapt to their environment.
D) higher density than water
