Do you know how cities began?

　　Long ago, the world had only a few thousand people. These people moved from place to place, hunting animals for food. No one knows how or when these people learned about growing food. But when they did, their lives changed. They began to live near one another. And so the first villages grew. Many people came to work in the villages. The villages grew very big. From there the cities began. joozone.com

　　When machines came along, life in the villages changed again. Factories were built. More and more people lived near the factories. The cities grew very big.