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 (:
Answer:
<h3>MAP OF THE PHILIPPINES</h3>
Explanation:
<h3>#BRAINLIESTBUNCH</h3>
I think its because we don't know how to harness it, with out making things explode.