(D) It uses enzymes to liquefy food and kill bacteria to be further digested in the intestines.
If you don't use them they get stored as glycogen, for later use. buy if you're not active, it can lead to obesity.
When you observe and compare specific physical traits of different birds you will learn that some birds have characteristics that help them live and survive in their own habitat that other birds may not have but make up those birds have characteristics that help them in their own habitat.
