Respuesta :
Answer:
Muscles move body parts by contracting and then relaxing. Muscles can pull bones, but they can't push them back to the original position. So they work in pairs of flexors and extensors. The flexor contracts to bend a limb at a joint.
Explanation:
if u want an answer to look like you wrote it, you could say something like “muscles expand and contract and work with your bones. this is what creates movement” or something along the lines of that.
