Types of transportation are trains, buses, cars, airplanes and so on. 交通工具的类型分为：火车、公交车、汽车、飞机等等。

　　They are for people or goods to move from one place to another. 它们是用来把人或货物从一个地方运到另一个地方的。

　　What is the most popular tansportation for students? 学生中最受欢迎的交通工具是什么呢？

　　It is a school bus. 那就是校车。

　　Why do you think school buses are yellow? 你认为校车是黄颜色的原因是什么呢？

　　It is because people can see yellow very fast, so this can prevent an accident. 这是因为人们很快就能看到黄颜色，这样就能避免发生交通事故。