《2022高校英语六级改革模拟练习：长篇阅读（6）》由会员分享，可在线阅读，更多相关《2022高校英语六级改革模拟练习：长篇阅读（6）（6页珍藏版）》请在金锄头文库上搜索。
1、2022高校英语六级改革模拟练习：长篇阅读（6）Passage TwoWords: 1,103How Ozone Pollution WorksA) The weather report on the radio or TV tells you that it is going to be sunny and hot and that an orange ozone alert has been issued. What is ozone? What does an orange alert mean? Why should you be concerned about it? In this
2、 article, we will examine what ozone is, how it is produced, what health hazards it poses and what you can do to reduce ozone pollution.B) Ozone is a molecule of three oxygen atoms bound together (O3). It is unstable and highly reactive. Ozone is used as a bleach, a deodorizing agent, and a steriliz
3、ation agent for air and drinking water. At low concentrations, it is toxic. Ozone is found naturally in small concentrations in the stratosphere, a layer of Earths upper atmosphere. In this upper atmosphere, ozone is made when ultraviolet light from the sun splits an oxygen molecule (O2), forming tw
4、o single oxygen atoms. If a freed atom collides with an oxygen molecule, it becomes ozone. Stratospheric ozone has been called “good” ozone because it protects the Earths surface from dangerous ultraviolet light.C) Ozone can also be found in the troposphere, the lowest layer of the atmosphere. Tropo
5、spheric ozone (often termed “ bad ” ozone) is man - made, a result of air pollution from internal combustion engines and power plants. Automobile exhaust and industrial emissions release a family of nitrogen oxide gases (NOx) and volatile organic compounds (VOC), by-products of burning gasoline and
6、coal. NOx and VOC combine chemically with oxygen to form ozone during sunny, high- temperature conditions of late spring, summer and early fall. High levels of ozone are usually formed in the heat of the afternoon and early evening, dissipating during the cooler nights.D) Although ozone pollution is
7、 formed mainly in urban and suburban areas, it ends up in rural areas as well, carried by prevailing winds or resulting from cars and trucks that travel into rural areas. Significant levels of ozone pollution can be detected in rural areas as far as 250 miles downwind from urban industrial zones.E)
8、You can make ozone test strips to detect and monitor ozone levels in your own backyard or around your school. You will need corn starch, filter paper (coffee filters work well) and potassium iodide (can be ordered from a science education supplier such as Carolina Biological Supply or Fisher Scienti
9、fic). Basically, you make a paste from water, corn starch and potassium-iodide, and you paint this paste on strips of filter paper. You then expose the strips to the air for eight hours. Ozone in the air will react with the potassium iodide to change the color of the strip. You will also need to kno
10、w the relative humidity, which you can get from a newspaper, weather broadcast or home weather station.F) When you inhale ozone, it travels throughout your respiratory tract. Because ozone is very corrosive, it damages the bronchioles and alveoli in your lungs, air sacs that are important for gas ex
11、change. Repeated exposure to ozone can inflame lung tissues and cause respiratory infections.G) Ozone exposure can aggravate existing respiratory conditions such as asthma, reduce your lung function and capacity for exercise and cause chest pains and coughing. Young children, adults who are active o
12、utdoors and people with respiratory diseases are most susceptible to the high levels of ozone encountered during the summer. In addition to effects on humans, the corrosive nature of ozone can damage plants and trees. High levels of ozone can destroy agricultural crops and forest vegetation.H) To pr
13、otect yourself from ozone exposure, you should be aware of the Air Quality Index (AQI) in your area every dayyou can usually find it in the newspaper or on a morning weather forecast on TV or radio. You should also be familiar with the U.S. Environmental Protection Agency (EPA) guide for ozone-alert
14、 values.I) What do the numbers in the AQI mean? The AQI measures concentrations of five air pollutants: ozone, sulfur dioxide, particulate matter, carbon monoxide and nitrogen dioxide. The EPA has chosen these pollutants as criteria pollutants, but these are not all of the pollutants in the air. The
15、se concentrations are compared to a standard set out in federal law. An index value of 101 means that all of the criteria pollutants are at the maximum level that is considered safe for the majority of the population. To reduce your exposure to ozone, you should avoid exercising during afternoon and
16、 early evening hours in the summer.J) There are several ways you can help to decrease ozone pollution. Limit using your automobile during afternoon and early evening hours in the late spring, summer and early fall. Do not use gasoline-powered lawn equipment during these times. Do not fuel your car during these times. Do not light fires or outdoor grills during these times. Keep the engine of your car or boat tuned. Make sure that your tire
