The structure of the spinal cord can be described as(1) composed of thirty-one segments(2) having a cervical enlargement, lumbar enlargement, and two deep longitudinal grooves(3) a central core of gray matter that is surrounded by white matter(4) having gray matter that is composed of myelinated nerve fibers

(1) composed of thirty-one segments

Explanation: Spinal Cord Nerve Branches contains 31 segments pairs of spinal nerves. Each nerves are form,from both combination of posterior and anterior roots.

a. the production of carbon dioxide through the process of photosynthesis

i think its white blood cells

i hope this