提高听力同时，你还可以了解到美国历史上的一些重要事件。请感兴趣的你一听为快吧！
The most recent Ice Age was about 35,000 years ago. Much of the world's water was frozen into big sheets of ice. A land bridge - as wide as 1,500 kilometers - joined Asia and North America. By 12,000 years ago, humans lived throughout much of what now are the Americas. The first "Americans" crossed the land bridge from Asia. Historians believe that they lived in what now is Alaska for thousands of years. They moved south into today's mainland United States. They lived by the Pacific Ocean in the northwest, in the mountains and deserts of the southwest, and along the Mississippi River in the midwest.
最近的冰期大约是在35000年前。世界的水大部分都被冻成大片的冰。一个1500千米的大陆桥连接着亚洲和美国的北部。到了12000年前，人类居住在现今为美洲的各个地区。第一个穿过大陆桥的“美国人”来自亚洲。历史学家认为他们住在阿拉斯加几千年了。他们向南迁移到现在美国本土上。他们住在靠近太平洋西北地区、 山区和沙漠的西南部，与中西部地区密西西比河沿岸。