<span>At first, it seems as thought Colonel Graff has arrived at the Wiggin household to confront Ender about his previous encounter with Stilson, possibly taking him away to a place where he would be of no danger to anyone else. When Ender tell's the Colonel why he kept striking Stilson long after he had hit the ground, it was clear that all Graff wanted, was to see if Ender was adequate for Battle School. He'd already seen his physical strength, but was yet to find out his logical reasoning.</span>
Answer: cerebrum, cerebellum, and brainstem
Explanation: Cerebrum: is the largest part of the brain
brainstem is the posterior part of the brain adjoining, and structurally continuous with, the spinal cord
cerebellum (which is Latin for “little brain”) is a major structure of the hindbrain that is located near the brainstem
It acts an insulator on the neurons. The neurons are covered with it and hence the nerve impulses have to jump over the myelin sheath to reach other neurons. This causes nerve impulses to move rapidly from neuron to neuron.