The part of a fish that helps them breathe underwater. Fish force water through their gills, and use them to get oxygen out of the water so they can breathe.

Technology that helps a diver swim and breathe underwater. One or two tanks of compressed (squashed) air are connected by a hose to the divers mouthpiece, and the tanks are strapped to the divers back.

Lungs are the major organs that help with breathing. When you breathe in, the lungs in your chest lungs fill with air. One of the major jobs of the lungs is to filter a special gas called oxygen out of the air and deliver it to your blood so it can help your body keep working and stay alive.