【正确答案】 C

【答案解析】[听力原文]
The automobile is almost the symbol of America. Henry Ford, by mass-producing cars, put America on wheels. The automobile quickly changed American manners and morals and it ended the isolation of many rural people. The early availability of automobiles, coupled with open land adjacent to cities, led to urban sprawl.
Today America has over 110 million miles of streets and roads which can-y 160 million licensed automobiles, trucks and buses. That means that there is a vehicle of some sort for every 1.5 Americans. 70 percent of all Americans are licensed to drive. Plentiful cars mean poor public transportation, however.
Gaining a driver"s license in America is fairly simple. Most young people take a driver"s training course in high school, others are instructed by their parents or a friend. In most states the minimum driving age is 16.
Purchasing a used car in America can be inexpensive. Cars are on the market for as little as $300 but their maintenance costs are high. Insurance is an expensive factor in operating a car.
Detroit is the center of the transportation industry in the United States. America once made big, inefficient autos but the gasoline crisis of the 1970s ended that. The Japanese experience in manufacturing good medium and small-sized automobiles has brought serious competition to the American auto industry. Today, many Japanese cars are common on the United States highways.