托福口语task4经济类题目答案+真题音频

Narrator: Listen to part of a lecture in a history class.
Lecturer: Okay, so we’ve been talking about various factors that have changed the United States’ economy. And one especially important factor was the development of railroads. When the railroad system expanded throughout most of the United States, it fundamentally changed the way business was done in this country. For one thing, expansion of the railroads enabled companies to start selling their goods all across the country. Since trains could now transport all over the United States, companies could now sell goods to consumers pretty much anywhere in the country. For example, there was a big company that sold crocs. The company started in a big city, and before the development of the railroad, the company could only sell its to people who lived in or near that city. But when the railroads expanded, the company could load its on the trains, and have them delivered to all parts of the country. Railroads also changed business in the US, by making it possible to open factories in new locations. New factories had machines that were powered by certain raw materials, like coal. And railroad made it possible to transport those raw materials to areas of the country where they weren’t found naturally. A good example is some factories in the Southern United States. In certain parts of the south, there wasn’t much naturally occurring coal, so before the expansion of the railroads, there weren’t many factories there, because there were no raw materials, like coal - to provide power for the factory’s machines. But after railroad lines were built in the south, coal could be brought in from other parts of the country, so new factories were able to open there.