[填空题]Acid rain may damage trees, soils and accelerate the decay of buildings.

[填空题]Acid rain may damage trees, soils and accelerate the decay of buildings.

[填空题]results in "Acid rain"

[单项选择] Researchers generally agree that acid rain arises primarily from the burning of coal and oil. The emissions contain oxides of nitrogen and sulfur, which can be carried hundreds of miles on the prevailing westernly winds. They eventually return to earth as dry gases and particulates and react with ground waters to form nitride or sulfuric acid. They may also be converted to the acids in the atmosphere by chemical processes that are still not fully understood. However the acids are formed, they have already been charged with a substantial list of damages. Corrosion of metal structures in windward areas of the country has been well-documented, but is a relatively minor entry on the list. Other forms of damage are far more insidious and longer-lasting. There is evidence, for example, that the acids leach heavy metals--aluminum, lead, and mercury-from the soil, which then poison plant roots and deprive them of vital nutrients. In lakes and rivers the acid alters the blood chemistry i
A. Chemical processes in the atmosphere.
B. Dry gases and particulates.
C. The burning of coal and oil.
D. The prevailing wind.

[单项选择]
The increasing variety and prevalence of pollution presents the world with many extremely daunting problems, air pollution in particular ranks among the most serious. In the following text, air pollution and acid rain caused by automobiles will be discussed. Certain solutions to the problem will be provided in the conclusion.
It is widely known that cars are the main cause of air pollution in cities, accounting for 60% to 90% of all air pollution. This will get worse as the number of cars increases in urban areas. How do cars cause air pollution First we must examine how a car works. There’s a mixture of petrol in the car’s internal combustion engine which create the force for the automobile to move. Unfortunately, in this process there are some poisonous chemicals which remain; these poisonous chemicals mainly come out of the car through the exhaust, it’s not just what comes out of the car e
A. solvable
B. frightening
C. promising
D. intrepid