8. What is the most important organ of the central nervous system?
a. Brain
b. spinal cord c. spinal column
d. brain stem
9. What organ of the skeletal system protects the brain?
a. Ribs
b. skull
c. pelvis
d. vertebrae
10. What is the largest body organ that receives stimulus from the outside environment?
a. Eye
b. skin c. nose
d. ears​