求翻译：目前，我国一些大城市的汽车尾气排放是城市大气污染的主要源头，而近年来随着人们环保意识的不断提高，为防治汽车有害物的排放对环境的污染，许多清洁燃料被人类所开发、利用。是什么意思？

At present, some of the major cities of vehicle exhaust emissions is a major source of urban air pollution, and environmental awareness in recent years as people continue to improve for the prevention of harmful emissions vehicle pollution of the environment, many developing clean fuels by humans, u

At present, some of our major cities for automobile exhaust emissions is the main source of air pollution in cities in recent years, with the continual increase in the awareness of the importance of environmental protection to combat vehicle harmful emissions, pollution of the environment in many cl

At present, our country some big city automobile exhaust emissions is the city air pollution main source, but in recent years along with the people environmental protection consciousness unceasing enhancement, for prevented and controlled automobile harmful the emissions to the environment pollution

At present, China's auto emissions in some major cities is the main source of urban air pollution, and in recent years, as environmental awareness continues to increase, for the control of pollution from car emissions of harmful substances on the environment, many is human development, using clean f

At present, our country some big city automobile exhaust emissions is the city air pollution main source, but in recent years along with the people environmental protection consciousness unceasing enhancement, for prevented and controlled automobile harmful the emissions to the environment pollution