The (1)__ is the most important structure that acts as a relay between the body and the brain. It extends from (2)__ to the lower backbone. It has (3)__ matter in inner surface and (4)__ matter in the periphery.

The (1)__ is the most important structure that acts as a relay between

1.	The (1)__ is the most important structure that acts as a relay between the body and the brain. It extends from (2)__ to the lower backbone. It has (3)__ matter in inner surface and (4)__ matter in the periphery.
Answer» The (1)__ is the most important structure that acts as a relay between the body and the brain. It extends from (2)__ to the lower backbone. It has (3)__ matter in inner surface and (4)__ matter in the periphery.