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6) dilute [ ] – разжижать, разбавлять, обескровливать, выхолащивать, слабеть, разрежать
7) airborne [ ] – переносимый по воздуху
8) waste [ ] – пустыня, потери, убыток, отходы
(Narrator) Questions below refer to the following talk on groundwater.
(Man) Groundwater is a vital source of drinking water and irrigation in the U.S. and other countries. Thou-
sands of sources are found throughout the country. The economic forecasts show that its use will grow due to
increased population, industrialization, and agricultural irrigation. Groundwater is not unlimited, and this
essential form of the earth's resources may be depleted. Its supply cannot be renewed as quickly as that of
rainwater, and some sources may disappear permanently. Another consideration to worry about is that con-
tamination of groundwater has occurred in various places in the United States, so some of its sources are no
longer potable. When groundwater is contaminated, it cannot be cleansed as simply as surface water because
the flow of ground-water is slow and not turbulent, and contaminants cannot be dispersed and diluted by new
water additions. Airborne bacteria that help cleanse surface water don't have access to groundwater flows.
Because groundwater is not in contact with the oxygen in the atmosphere, only a small number among doz-
ens of bacteria types can reach it to accelerate the cleansing processes. Once groundwater at a particular
source is contaminated, it may take several hundred years to cleanse it of degradable wastes.
(Narrator)
Exercise 1 Answer the questions.
1 According to the speaker, why is groundwater important?
2 What are the causes of decrease in the groundwater supply?
3 How long does it take to cleanse a groundwater supply?
Exercise 2 Translate from Russian into English.
1 Многие ресурсы земли могут быть исчерпаны по разным причинам. Одна из них – загрязнение
источников.
2 Источники воды могут быть очищены от отходов (wastes), но на это могут уйти сотни лет.
3 Ускорение любого процесса роста может привести к нарушениям процесса развития.
4 Бурные течения порой представляют собой опасность для жизни людей и животных.
5 Разогнать и разбавить загрязненные источники могут чистые (новые) потоки воды.
6 Благодаря разумной деятельности человека можно предотвратить глобальное загрязнение окру-
жающей среды, которое по прогнозам может произойти в недалеком будущем.
Exercise 3 Retell the story.
Text 1 Read, translate and retell.
Almon Strowger, an American engineer, constructed the first automatic telephone switching system, which
had a horizontal, bladelike contact arm, in 1891. The first commercial switchboard based on his invention
opened in La Porte, Indiana, a year later and was an instant success with business users. To access the sys-
tem, the caller pressed buttons to reach the desired number and turned the handle to activate the telephone
ringer. During the same year, Strowger's step-by-step call advancement technology was implemented in the
long-distance service between New York and Chicago when it proved to have the capacity of carrying sig-
nals through cable-joint extensions.
The first actual dial telephones, patented by Lee De Forest in 1907, were installed in Milwaukee in 1896. In
1912, their sound transmittal apparatus adapted an electronic tube to function as an amplifier. Transatlantic
radio-telephone service linked New York and London in 1927. However, the long distance coaxial cable,
which was hailed as unprecedented, came on the scene in 1936 connecting New York and Philadelphia. The
Bell Laboratories research facility came up with the transistor to replace the cumbersome vacuum tube, thus
diminishing the size of the electronic switch system to about 10 percent of that of the original. Crossbar
switching, installed in terminals in 1938, operated on the principle of an electromagnetic force, which rotated
horizontal and vertical bars within a rectangular frame and brought contacts together in a split second. A
technological breakthrough in the form of underseas cables between the United States and Hawaii was im-
plemented almost twenty years later.
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