阅读下面短文，从每题所给的A、B、C、D四个选项中选出能正确回答所提问题或完成所给句子的最佳答案。
On a small farm（农场）, there is no school. A bus is the school. The driver of the bus is the teacher. It's a school bus, but it doesn't take the children to school. It just goes round from place to place, and sometimes it comes to this farm. The bus will stay here for three months. Every time when the bus comes, the farmers will come, running to it, shouting（喊） and laughing（笑）. They warmly welcome the school bus.
When the bus is on the farm, in the morning, the teacher teaches the small children. In the afternoon, the bigger children come to have their lessons because they must work in the morning. At night, the fathers and mothers come to school. They want to learn, too. And the farmers hope （希望） that they can have a real school on their farm.
