[填空题]The acid rain destroys the protection on tree leaves, which makes the plants more vulnerable to disease.

[填空题]The acid rain destroys the protection on tree leaves, which makes the plants more vulnerable to disease.

[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. Western parts produce much less than a quarter of sulfur oxide emissions
B. Western soils can neutralize the acid
C. Westernly wind spread participants out of the western regions
D. chemical industry is less developed in the western states

[填空题]Acid rain is produced when atmospheric moisture combines with pollutants from paper mill (造纸厂) , factories and automobiles.

[填空题]The acid rain problem has improved a lot.

[填空题]Acid rain problems are worse in the northern hemisphere because there is more ______ in this region.

[填空题]Acid rain means the precipitation in the form of rain, snow or hail which is more acidic than normal.

[单项选择]Acid rain leads to fish mortality. Many species of fish cannot survive in aquatic environments where the pH is below 5.0. If the water is too acid, the gill systems of many kinds of fish can be damaged. (61) , the acid alters the blood chemistry of all fish. As a result, the fish population in an acidic environment decreases (62) becomes extinct. Approximately 20 percent of the lakes in Scandinavia are without fish. Moreover, in Nova Scotia the (63) salmon industry may be threatened by the decrease of salmon in rivers and streams. The impact is also (64) in the waters of Ontario and Quebec, where fish populations are (65) the decline.
What potential remedies exist for the acid rain (66) The experts disagree. Some say new environmental laws should be (67) to control the emission of pollutants in the atmosphere. Some say that if we had known how serious acid rain was, we would have planned (68) to prevent it. (69) , all
A. possibility
B. perspective
C. occurrence
D. opportunity