交通运输：汽车、火车、飞机、轮船是当代的主要运输工具，它们烧煤或石油产

Transportation: Automobiles, trains, airplanes, and ships are the main means of transportation in modern times. The exhaust gas produced by burning coal or oil is also an important pollutant. Especially in cities, the amount of cars is large and concentrated, and the pollutants emitted by tail gas can directly invade human respiratory organs, causing serious air pollution in cities and becoming one of the major air pollution sources in big cities. Exhaust gases from automobiles are mainly carbon monoxide, sulfur dioxide, nitrogen oxides, and hydrocarbons. The first three substances are very harmful.

Transportation: Automobiles, trains, airplanes, ships are the main means of transportation of our time, and the exhaust gases produced by burning coal or oil are also important pollutants. In particular, the city's cars, large and concentrated, exhaust emissions of pollutants can directly attack the human respiratory organs, the city's air pollution is very serious, become one of the main sources of air pollution in big cities. The exhaust gases emitted by automobiles are mainly carbon monoxide, sulfur dioxide, nitrogen oxides and hydrocarbons, and the first three substances are very harmful.

Transportation: automobiles, trains, airplanes and ships are the main means of transportation in the contemporary era. The exhaust gas produced by burning coal or oil is also an important pollutant. In particular, the amount of cars in the city is large and concentrated. The pollutants emitted by the exhaust gas can directly invade the respiratory organs of human beings, which causes serious air pollution in cities and becomes one of the main air pollution sources in big cities. Automobile exhaust gas mainly includes carbon monoxide, sulfur dioxide, nitrogen oxides and hydrocarbons, and the first three substances are very harmful.<br>