题目内容：

Americans drove more miles in 2015 than any year since the U.S. government started keeping records 45 years ago. The U.S. Department of Transportation (USDT) recently reported that Americans drove a record of 3.148 trillion miles last year. In case you are wondering, that is enough to take 337 round trips from Earth to Pluto.

There are a number of reasons why Americans are driving more miles. The social experts agree that the first is the price of gas, which has dropped to the level of the year 2004 in the past year. The American Automobile Association (AAA) said that the average price of gas was just $1.71 a gallon. That could be the lowest price since 2004.

P.J. Sriraj, a director of the Urban Transportation Center at the University of Chicago, notes that the lower cost to fill up a car is just one reason. Another reason is that more Americans are back to work after the 2008 economic recession, and they drive to their jobs.

Besides, more Americans have to travel a long distance every day between home and the office. There are a lot of Americans who must travel more than 45 miles per day for their jobs. And as for many, there is not enough public transportation.

Because of the heavy traffic, roads are becoming more and more crowded. While modern cars are more fuel-efficient, the improvement is not enough to offset more cars on the road. “There is no doubt that driving more will make the air dirtier,” said P.J. Sriraj. And many Americans showed a great concern in a recent survey.

1.The USDT report shows that in 2015 ________.

A. Americans drove record-breaking miles

B. Americans drove 3.148 trillion miles a day

C. Travel to Pluto was popular with Americans

D. The government began to record driving miles

2.P.J. Sriraj thinks the reason why Americans drove more miles is ________.

A. the low prices of gas and cars    B. the 2008 economic depression

C. the Urban Transportation Center    D. more people’s coming back to work

3.What makes many Americans worried?

A. Having to drive far to work.    B. Having no public transportation.

C. Too many cars’ pollution of the air.    D. Small improvement of modern cars.

4.How is the whole passage developed?

A. By explaining causes.    B. By giving examples.

C. By following time order.    D. By making comparison.