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. | 
