Magtanong at makakuha ng eksaktong mga sagot sa IDNStudy.com. Magtanong ng anumang bagay at makatanggap ng detalyadong sagot mula sa aming komunidad ng mga eksperto.
Answer:
Muscles provide the tug on the bones needed to bend, straighten, and support joints. Muscles can pull on bones, but they can't push them back to their original position, so the muscles work in pairs of flexors and extensors.