Choose the word that can substitute the given sentence.

An internal or external framework of bones

Skeleton

The word that can substitute the given sentence "an internal or external framework of bones" is skeleton.

• Spine is the part of the skeleton that runs along the back and supports the head and torso.
• Skull is the bony structure that protects the brain.
• Skin is the outer covering of the body. It is not made of bones.

Skeleton is the correct answer because it is a complete framework of bones that supports the body and protects the internal organs. It is made up of 206 bones in an adult human.