Final answer:
The muscular system is responsible for moving the bones in the body, allowing us to wave to a friend.
Step-by-step explanation:
The system responsible for moving the bones in the body so you can wave to a friend is the muscular system. The muscles in our body work together to generate force, allowing us to move various parts of our body, including our bones. When you wave to a friend, the muscles in your arm contract and relax, causing the bones in your arm to move in a waving motion.
Learn more about Muscular system and bone movement