I think this is ovulation. Not a 100% sure
was made of bone or metal in wide variety of designs
Explanation:
Muscular endurance is a process of making the muscles active. Muscles are activated by using them with a force and doing effort with them in a repetitive manner. So if a person wants muscular endurance in a gym, he is given a plan to do approximately 10 exercise machines which activate his muscles. These machines are set in a series to put pressure on your whole body muscles. There would be some machines that would target your arms, shoulders and back muscles, other machines may target your abs and core, while others will target your legs and lower back muscles. In this way, muscles are activated.
