Question

use the drop-down menus to complete the sentence. the central nervous system contains, which is the center of the nervous system, and, which coordinates the spinal cord glands the brain muscles

Explanation:

The central nervous system (CNS) consists of the brain and the spinal cord. The brain is the center of the nervous system, and the spinal cord coordinates (and transmits signals). Glands are part of the endocrine system, and muscles are effectors in the nervous system but not part of the CNS. So the first drop - down should be "the brain" (as it's the center) and the second should be "the spinal cord".

Answer:

First drop - down: the brain; Second drop - down: the spinal cord