a fish is a kind of aquatic animal & gills are used for breathing water by aquatic animals ->  gills are a part of a fish used for breathing water  gills are a part of a fish used for breathing water & breathing is when a gill converts from oxygen in water into oxygen in blood ->  gills are a part of a fish used for breathing oxygen in water  gills are a part of a fish used for breathing oxygen in water & in water means underwater ->  gills are a part of a fish used for breathing oxygen underwater  an animal requires oxygen for survival & adaptations are used for survival ->  an example of an adaptation is something that is used for getting oxygen  gills are a part of a fish used for breathing oxygen underwater & an example of an adaptation is something that is used for getting oxygen -> gills are a kind of adaptation for getting oxygen underwater