The past and the present are very different. 过去与现在非常不同。

　　Let's imagine our life without televisions, cars, telephones and computers. 让我们想象一下没有电视、汽车、电话和电脑的生活。

　　Do you think you can live in such a world? 你认为你能生活在这样的世界吗？

　　People watched plays in the past, and people watch television shows in the present. 过去人们看戏剧，现在人们看电视节目。

　　People rode on horses in the past, and people ride cars in the present. 过去人们骑马，现在人们开车。

　　People sent letters in the past, and people send emails in the present. 过去人们寄信，现在人们发电子邮件。