Why is the world with animals better than without

In the city wild animals are allowed in circuses, zoos, water parks and dolphinariums. Some citizens contain the wild animals in his apartment (e.g., foxes). In the city wild animals are kept in artificial conditions, which differ sharply from the natural. Therefore the wild beasts, born or long lived in the zoo, killed in the natural environment. Of course, the artificial conditions -- not the best way. But it is often necessary to save species close to extinction. In addition, these institutions have great educational work, introducing us to the animal world of our planet.