听力原文：M: I just came back from a trip to China and I was very impressed with the long history of that country. W: Last year I visited Europe. It was interesting to see the ancient ruins there, too. M: When I look at our country's history, I begin to sense what a young country the States really is. W: Yes. There are many countries whose histories were ancient when ours was just beginning. M: The first English settlers arrived in America about the time the last Chinese dynasty began. W: I believe one reason America has been able to be so successful in so many aspects is that it had no ancient traditions to bind it down. M: Why would you say that? The settlers to America came from countries all over the world and must have brought their traditions with them. W: Yes, they did and those traditions have enriched the American heritage however, their purpose in coming to this new country was so they could make a change from the way they were living. Most immigrants to America were penniless. They came here to take advantage of a new way of life. M: Sometimes I think we ignore the history of the native people encountered here in the Americas, both North and South. W: Well, that's true. I've noticed, however, that the remains of civilizations in North America don't appear to be as ancient as those found in Mexico or Central and South America. M: Those civilizations must have been as ancient as what I saw in China. They didn't have an influence on the modern countries, though. Why is that? W: It's because those were dead civilizations. For some reasons, the traditions from those civilizations did not carry on to the surviving natives of the land. M: Do you think that's the reason, or is it that the immigrants who exerted authority over the natives were able to suppress their traditions? W: I would think both are explanations. (20)