【正确答案】 C

【答案解析】[听力原文] 17-20
For the past few weeks, we have been discussing national energy conservation alternatives for the future. Today I'm going to talk about what one community's presently doing to conserve energy. The people of Davis, California, have succeeded in cutting their energy consumption by 1/3 since 1973. The first energy saving action that was taken in the early 70's was the legislation of street building codes. All new houses in Davis must have the proper insulation so that heat will not escape unnecessarily during the winter. New houses must also face north or south, so that they will not be overheated by the sun in summer. The law definitely has had effect. Since 1976, there has been a 50 percent saving in the amount of natural gas and electricity used in heating and air-conditioning. There are other energy saving features about Davis. Buses, partially supported by the city, transport university students throughout the area. There are 24 miles of bicycle paths, and today there are twice as many bicycles as cars in the city. By reducing the available parking space, the city council has succeeded in reducing the number of cars in the city every day. Another benefit of the reduced parking space is the greater number of small cars. People are saving gas because they are choosing not to drive, or because they are driving fuel-economic cars. Davis, California, has become an energy saving model for other cities. Time is up for today. Next week, we'll return to our regular topic of national energy alternatives.