L) With continued conservation and reduction practices, adherence to ozone-pollution warnings, research and government regulation, ozone-pollution levels should
continue to fall. Perhaps future generations will not be threatened by this environmental pollutant.
M) The thing that determines whether ozone is good or bad is its location. Ozone is ‘‘good，，when it is in the stratosphere. The stratosphere is a layer of the atmosphere starting at the level of about 6 miles (about 10 kilometers) above sea level. The stratosphere naturally contains about six parts per million of ozone, and this ozone is very beneficial because it absorbs UV radiation and prevents it from reaching us.
N) Ozone is “bad” when it is at ground level. Ozone is a very reactive gas that is hard on lung tissue. It also damages plants and buildings. Any ozone at ground level is a problem. Unfortunately, chemicals in car exhaust and chemicals produced by some industries react with light to produce lots of ozone at ground level. In cities, the ozone level can rise to a point where it becomes hazardous to our health. That’s when you hear about an ozone warning on the news.
1. When ultraviolet rays from the sun separate an oxygen molecule into two single oxygen atoms in the stratosphere, the combination of a single oxygen atom and an oxygen molecule forms ozone.
2. You can make ozone test strips by yourself to find out about ozone levels in your own locale.
3. Long-time exposure to ozone is badly harmful to our respiratory system.
4. Chemicals in industrial waste gas and vehicle exhaust react with light to form lots of ozone at ground level.
5. Internal combustion engines and power plants cause the artificial tropospheric ozone, also known as “bad” ozone.
6. Ozone is very helpful because it absorbs UV radiation and separates us from it.
7. Using gasoline-powered lawn equipment in the late spring, summer and early fall may increase ozone pollution.
8. Ozone pollution occurs in urban and suburban areas as well as in rural areas.
9. In order to decrease ozone pollution, the EPA has set up more rigorous air-quality standards.
10. Pay close attention to the Air Quality Index in your area every day can keep you away from ozone exposure.
以上是为大家总结的2014年12月20日英语六级预测阅读题，希望考生在接下来的复习中可以加以运用，考试在即，广大考生要继续努力备战，争取顺利过关!
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