托福阅读文章的选材范围极其广泛，涉及有自然科学和人文科学以及社会科学。从选材范围可见托福阅读的文章内容对考生知识存储量的广度有一定的要求。虽然所涉及的专业知识只是介绍性的，但如果我们事先了解这些内容，对于文章的理解和做题的准确度方面也会起到事半功倍的效果。

最近的九月下旬的考试，出现了和北美特大城市有关的内容，而且是重复话题。现在就带大家一起来了解下相关知识～

美国已经形成了具有全球影响和经济核心竞争力的三大城市群（Megalopolis）：东北部大西洋沿岸以纽约为中心的城市群、北美五大湖以芝加哥为中心的城市群、西南部太平洋沿岸以洛杉矶为中心的城市群。下面我们就一起来看看阅读中是如何描述特大城市群形成的原因的吧～

Inland areas were the home of the agriculture and manufacturing industries in the United States. And there was a great demand for imported products. Meanwhile, products produced in inland areas also needed access to the overseas markets. The east coast of the United States provided ports to meet that demand. As a result, the megalopolis, which is a cluster of cities, emerged here.

美国的农业和工业主要在内陆地区，对进口产品有很大的需求，同时内陆产品也需要海外市场。美国东海岸提供了港口满足需求。因此，这里城市聚集，被称作特大城市群。

Megalopolis included regional central cities as well as surrounding satellite cities and rural areas. These areas do not share a common administrative center, but they were closely linked. The convenience of interstate transportation attracted more people to make this place home.

特大城市群包括主要的城市，也包含了周边的小城市和乡村(rural areas)。这些地区没有统一的政府管理，但是又相互联系。这个地方的州际交通(interstate transportation)的便利使得更多的人安家。

Because there were many waterfalls, different methods were needed to transport goods. It boosted the construction of warehouses and employed a massive number of laborers. As a result, the megalopolis had experienced further development.

因为这里有很多瀑布，所以货物需要以不同的方式来运输，这促进了仓库(warehouse)的建设和劳动力的雇佣，从而使得城市群进一步发展。

However, as globalization deepened and the infrastructures of the east coast megalopolis wore out over time, the megalopolis gradually lost its advantages to compete on a global level. The local government officials decided to restore its competitiveness through taxation.

但是由于基础设施老化，和国际竞争日益加剧，导致美国东海岸特大城市群失去竞争优势。政府官员决定通过征税(levy taxes)更新设施，恢复其在国际市场的竞争力。