本文为了叙述方便起见,其中有的地方也要述及到有关柴油汽车和液化石油气汽车的一些问题。一、大气污染据1974年的统计,当时世界上约有2亿4千多万辆汽车,而在1970年时美国就已超过了1亿辆。在一些国家里,小轿车的数量占汽车总数的60～80%以上,如美国占83%、英国占87%、法国占86%、日本几乎占一半。世界上汽车每年总计要排出2亿吨CO、44万吨HC、 This article for the sake of narrative, some of them also have to mention some of the issues related to diesel vehicles and LPG vehicles. I. Air Pollution According to the statistics of 1974, there were about 240 million vehicles in the world at that time, while in 1970 the United States had exceeded 100 million. In some countries, the number of cars accounts for more than 60-80% of the total number of cars. For example, the United States accounts for 83%, Britain accounts for 87%, France accounts for 86% and Japan accounts for almost half. In the world, cars emit 200 million tons of CO and 440,000 tons of HC each year,