What is transportation? 什么是运输工具？

　　It includes cars, subways, buses, trains, airplanes and ships. 它包括汽车、地铁、公交车、火车、飞机和轮船。

　　What happens if we don't have any transportation? 如果没有交通工具会怎么样呢？

　　We have to use our own feet. 我们只能徒步了。

　　How did people travel, when there were no cars, trains or airplanes? 没有汽车、火车或飞机时，人们是如何出行的呢？

　　People use animals for transportation. 人们用动物作运输工具。

　　Horses were the most popular types of transportation around the world. 马曾是世界上最受欢迎的一种运输工具。

　　But some countries also use elephants, camels and dogs, and they still do. 而有的国家还会用大象、骆驼和狗当运输工具，现在仍旧如此。

　　Those animals are slower than modern types of transportation. 那些动物比现代运输工具的速度要慢得多。

　　But riding an elephant must be much more fun than driving a car. 但是骑大象一定会比开汽车要有趣得多。