现代化生活已经离不开汽车 ,然而汽车尾气排放对大气造成的污染已成为严重困扰世界各大城市的环境问题。因此 ,控制车辆尾气排放 ,使用环保型车辆 ,已成为汽车工业发展的主流。我国是发展中的社会主义大国 ,经济建设迅速发展 ,人民生活水平不断提高和改善 ,由此带来对交通工具 Modern life can not be separated from cars. However, the pollution caused by automobile exhaust to the atmosphere has become a serious environmental problem that plagues major cities in the world. Therefore, the control of vehicle emissions, the use of environmentally friendly vehicles, has become the mainstream of the automotive industry. As a developing socialist power, our economy is rapidly developing and the living standards of the people are constantly improving and improving. As a result,