Acid rain forms in the upper atmosphere. There, sulfur dioxide and nitrogen oxides mix with water vapor. They mix with water vapor to form sulfuric acid and nitric acid. When the vapor condenses and rain falls, the acids fall with it. Every time acid rain falls in a lake, the level of acid in the lake rises. Over time, it can rise to the point at which plants and insects cannot survive. Without plants, which supply oxygen, and insects, which supply food, fish die. The lake becomes a dead lake.
The problem of acid rain has greatly increased in the last few years. Most of the blame for acid rain has been placed on industries. However, some people feel that ineffective air pollution laws are also to blame for the acid rain problem. A few years ago, many cities and states passed local air pollution laws. The laws were written to improve the air quality in the cities and states. However, the laws usually didn't say anything about the amount of pollution that an industry could pump into the air. Industries found a way to meet the new pollution laws without reducing the amount of pollution they released. They met the new standards by building taller smokestacks. With the taller smokestacks, air pollutants were released higher up into the atmosphere. The wind carried them far away from the polluting factory. To the people near the factory, the air seemed cleaner. However, the pollution that they once got was now coming down hundreds of miles away in the form of acid rain.
酸雨是一个非常严重的空气和水污染问题。 很多人都认为这是我们至今所面临的污染问题当 中最严重的。 科学家们说, 生存在美国和加拿大成千上万湖泊中的植物和动物已经遭受到酸 雨的破坏。 酸雨在高层大气中形成。在那里，二氧化硫和氮氧化物与水蒸气混合。它们与水蒸汽混合形 成硫酸和硝酸。当水汽凝结并降雨,酸性物质会随之下降。每次酸雨落在湖里，湖里的酸度 会渐增。随着时间的推移,酸度会增加到植物和昆虫无法生存的程度。没有植物提供氧气...