Given a scientific question, generate a correct answer to it.

Input: Consider Input: The pelvic girdle, consisting of a hip bone, serves to attach a lower limb to this?

Output: axial skeleton

Input: Consider Input: What consists of four major components: inorganic mineral matter, organic matter, water and air, and living matter?

Output: soil

Input: Consider Input: Free-flowing electrons enable what materials to conduct electricity and heat very well?
Output: metals