Zoos have been saving animals from being in danger. In fact, animals are considered as an important part of humans lives. Some people believed that zoos must be built outside cities because it causes a lot of noise and pollution.The majority says that zoos must be built inside cities because it is a means of entertainment and scientific researches Out in the wild, some animals would have a very little chance to survive, especially those on the endangered list. As we know, these animals are still hunted by poacher for their skins,bones, and other by products. Also, some of them have a more difficult time surviving in the wild by themselves due to pollution, destruction of their habitats, high level of competition for