Imagine you’re at lunch. Your nose smells pizza. Your legs move over to where hot lunch is being served. You have to balance the food and your milk in your hands, look around for a free seat, and then sit down. This may seem simple, but many different parts of your body have to work together to make all of that happen. To make sure your body can work correctly, even when it does many things at once, your body must be carefully organized. WHAT IS THE MAIN IDEA???