The levels of concentration the cell needs for sodium and potassium.

i think the answer is b.

hope it

answer; hypnagogic sensations)

i tried the eyeshadow trick you told me about and it worked so good i i did a yellow going into orange colors and it was bright and you could see it on my eyes

after receiving a stimus, the sensory receptors send(s) signals to the appropriate area of the body.  

the must be sensory neurons.  

hope its .