I Прочтите и устно переведите с 1-го по 5-ый абзацы текста. Перепишите и письменно переведите 3, 4, 5 абзацы текста
Перепишите и письменно переведите 3, 4, 5 абзацы текста.
DEPLETION OF THE OZONE LAYER
1. Ozone, the triatomic form of oxygen (O3), is primarily concentrated in a layer high above the earth within the stratosphere. While the actual amount of ozone in the atmosphere is small, its ability to absorb harmful ultraviolet rays from the sun makes it vital to humans.
2. In 1974 scientists first documented that man-made gases can interact with ozone and convert it to diatomic oxygen (O2), which offers no protection from ultraviolet radiation. While several gases have been linked to this ozone depletion process, the primary culprit seems to be chlorofluorocarbons (CFCs) which are gases involved in the greenhouse effect as well. CFCs are used in refrigeration, air conditioning, insulation, packing materials (fast food containers), and as propellant for aerosol cans.
3. These chemicals have already upset the state of equilibrium that has existed in the ozone concentration for millions of years. The hole in the ozone layer over Antarctica (which can be seen due to the unusual weather conditions of this region) has been growing larger each year. Scientists believe that variations in that region could serve as a gauge of depletion of the ozone layer in other regions of the world. This relationship appears to be true. A recent study (1991) found that the ozone layer over the midlatitudes has been depleted 2 to 3 percent since 1979.
4. The Environmental Protection Agency estimates that every 1-percent decrease in stratospheric ozone could result in 24,000 to 57,000 more cases of cataracts and 43,000 new cases of skin cancer each year in the United States. Increased ultraviolet radiation would also increase the effects of many diseases that affect the skin or start on the skin. Excessive ultraviolet radiation causes cell and tissue damage in many plants. This could result in a significant reduction in crop yields throughout the world.
5. What can be done? In 1987, 38 countries met in Montreal to sign an agreement — the so-called Montreal Protocol — to cut CFCs use in half by the end of the century. This historic first effort towards international control of an air pollutant is hopefully only the beginning.
II Прочтите 2-ой абзац текста и письменно ответьте на следующий вопрос:
What gases are considered to be the primary culprit in the ozone depletion process?
Контрольная работа № 5
(для специальностей ЭТФ)
Вариант 3
I Прочтите и устно переведите с 1-го по 5-ый абзацы текста.
Перепишите и письменно переведите 1, 2, 4 абзацы текста.
AIR POLLUTION
1. Pollution of the air by certain industrial processes, particularly by burning of coal, has been a concern for many years. However, it was not until thousands died because of air pollution, in such cities as London in the 1950s, that the first steps were taken to reduce the poisons that were routinely being emitted into the air we breathe. Two major sources of harmful emissions became the targets for initial action: utilities and industries, and motor vehicles. Steps were first taken to clean up smokestack emissions around power plants and industrial complexes. Attention was then focused on the sulfur oxides emitted from utility, commercial, and industrial stacks. At the same time devices were developed to cut back on emissions from motor vehicles.
2. Air quality management is a complex undertaking. It is complicated by the nature of air, and by the gases that are commonly considered its basic components. It is further complicated by the continual chemical changes that take place in the air as it moves from one location to another and by atmospheric forces.
3. Special understanding of city air pollution is needed because of great potential health hazards. Sources of pollution are more abundant in major cities than in small towns or rural areas. Often there are coal-fired power plants nearby; schools, universities, hospitals, and other institutions often burn oil as their heat source; industries use fossil fuels as a vital part of industrial processes; each individual home, burning oil, gas, or wood, adds to the pollution entering the city's air.
4. There are many other sources of pollution: motor vehicles, construction activities, dust generated in the city and from agricultural activities nearby, and thousands of vaporized chemicals, some of them toxic and hazardous.
5. Each year millions of dollars are spent to reduce the amount of pollution emitted into the atmosphere. Some control devices are already used to reduce emissions from smokestacks and automobile exhausts. However, even tighter controls may be needed in the future. It is an endless battle, one that is essential to safeguard human health and the natural environment.
II Прочтите 5-ый абзац текста и письменно ответьте на следующий вопрос:
Where are control devices already used?
Контрольная работа № 5
(для специальностей ЭТФ)
Вариант 4