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.
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.
很久以前，世界上只有几千人。这些人从一个地方到另一个地方，狩猎动物为食。没有人知道这些人什么时候学会种植食物。但是当他们这样做的时候，他们的生活改变了。他们开始住在一起。所以有了第一个村庄。许多人来到村庄工作。这个村庄越来越大。从那里开始出现城市。
当机器出现，再次改变村庄的生活。工厂被建立。越来越多的人住在附近的工厂。城市也变大了。