I believe that a zoo has many useful purposes.

 1. A zoo is a live educational place where people especially children can learn our nature and live animals. Children do not have many chances to see animals at firsthand. They just see them in books, TV, or games. If they see directly and touch them, they will love and treat more carefully them. They can learn that all live things are precious and they should not abuse animals.

 2. A zoo helps people who are tired in their life to relieve their stress. In zoo, we can feel nature through appreciating it. There are trees, flowers, water, animals and especially no cars. As we live in big cities, we get a lot of stress from noise of cars, people, or TV, and bad smells from gas of automobiles, big buildings, or factories. We sometimes want to escape there, but we do not have much time to travel to country side. A zoo will give your feeling refresh whenever you are tired without wasting too much time to move.

 3. A zoo helps to preserve our nature. In a big city, people want to build as many big buildings or apartments as they can to make money. If all places of a big city are occupied by grey buildings, it will be dangerous for our mental and physical health. A zoo will keep at least one place in which people can see green earth.