III Перепишите английские предложения, найдите и подчеркните в них зависимый или независимый причастный оборот. Переведите предложения на русский язык.

1. Alkali soils being brought into production and soils that have accumulated salts through the use of high salt-content water require leaching.

2. Principal crops grown under irrigation are corn, alfalfa, and sorghums, corn being the most important.

3. The amount of fresh water being small, we must use fresh water efficiently.

4. A new irrigation system having been built, some water problems were solved.

IV Перепишите и письменно переведите на русский язык следующие
сложные предложения, подчеркните в каждом английском предложении придаточные предложения условия.

1. If sea water did not contain harmful substances, it would be used for irrigation or drinking purposes.

2. There are comparatively few regions where irrigation would not be profitable if it could be cheaply provided.

3. Improving irrigation would be much easier if we could see what is taking place

below the soil surface.

V. Прочитайте текст "Methods of Water Application ", письменно ответьте на вопросы:

1. What factors will influence the choice of irrigation methods?

2. What is the objective of irrigation?

Methods of Water Application

Many factors, including topography, source, amount, and quality of water supply, permeability of the soil, slope of land, method of distribution of the water to the irrigator, precipitation during the irrigation season and the crop growth will influence the choice of methods.

The only objective of applying water to the field is to supply sufficient moisture to meet the needs of the growing crop. The soil in which the crop grows is a storage reservoir. Application of water fills the storage space in the soil and makes water available to the plant through its root system.

Therefore, the objective of irrigation is to apply water uniformly throughout the root zone in sufficient quantities to meet the plant needs, without erosion, with a minimum amount of deep percolation, and with a minimum amount of surface runoff.

ТЕКСТЫ ДЛЯ АУДИТОРНОЙ РАБОТЫ

The Supply of Water

The total amount of water contained in our planet is constant and invariable and can neither be increased nor diminished. It assumes а variety of forms, such as the oceans, moisture vapour, fresh water, lake water of varying degrees of salinity, and ice. As most of this water is locked away in the oceans, in snow fields, ice caps and glaciers, only а sma11 proportion is available in а form readily usable by man. Moreоvег, а great deal of the water in and on the land is polluted by minerals or by industrial waste and so frequently rendered unusable.

Of the water contained in the oceans, а very sma11 proportion daily changes its form and composition and is moved to the 1and, where it can be used by man and from where it returns to the oceans. This process, which has no beginning and no end, is known as the hydrologic cycle. It comprises а gigantic system operating in and on the land and oceans of the earth and in the atmosphere surrounding it. It is estimated that something like 80,000 cubic miles of water are evaporated each year from the oceans, together with approximately 15,000 cubic miles of water evaporated from the lakes, rivers, canals and land surfaces of the continents. This total global evaporation is exactly balanced by the total precipitation. of which approximately 24,000 cubic miles in the form of waterfa11 on the land surfaces and the rest on the oceans. This cyclical movement of water is divisible into three main stages. Firstly, solar radiation, acting upon the surface of the oceans, heats the surface layers and causes evaporation and the diffusion of water vapour upwards into the atmosphere. The water vapour, which at this stage is pure, is then transported great distances by the winds. During its movement across the oceans and over the land, it may become polluted in а variety of ways: by atmospheric dust, by particles of radioactive material or by industrial and domestic smoke.

In the second stage of the cycle, the air masses containing the water vapour are suddenly cooled. This cooling, which may occur for а number of reasons, though primarily as а result of the air masses being forced to rise over high ground, causes condensation to take place and rain or snow to be precipitated. Of this precipitation, some falls directly into the oceans, out of man's reach and some is too heavily polluted.

The third and final stage is that in which the water moves back, over and under the 1and, into the oceans, from which it came. Of the water which falls upon the land, some flows оvег the surface, some sinks into the soil, and some is taken uр by the roots of vegetation to be used by plants and subsequently released into the atmosphere by transpiration. If, for example, an average of thirty inches of rainfa11 reaches the land surface each year, approximately twenty-one inches will evaporate directly or be transpired by vegetation. Of the remaining nine inches, most will run directly to the oceans as surface runoff or permeate the rock materials beneath the surface to form underground water аnd, at а later stage, indirectly reach the oceans. Water which began in the oceans sooner or later returns to them. The only stage in the cycle at which man can, at present, intervene and make use of the water on а large scale is the third, and only then if the water is comparatively pure.

Упражнения

1. Найдите в упражнении слова, сходные с русскими словами, переведите словосочетания на русский язык без использования словаря:

the total amount; minerals of our planet; hydrological cycle; solar radiation; diffusion of water; radio-active mаterial; industrial smoke; the stages of the cycle; atmospheric dust; global evaporation; final stage; gigantic system, to balance condensation; the ocean of air

II. Определите, к каким частям речи относятся следующие слова и переведите их:

1) to use, the use, used, usable; 2) to divide, division, divided, divisible; 3) to vary, variation, variable, invariable; 4) to move, movement, moved, movable; 5) to compare, comparison, compared, comparable; 6) to permeate, permeability, permeable; 7) to measure, measurement, measured, measurable

Ill. Выпишите парами слова-синонимы:

to take place, to return, to occur, to come back, tо cause, to comprise, to use, to make use of, to involve, to force, average, upwards, under, beneath, downward, part, upward, downwards, the rest, proportion, the remainder, quantity, mean, amount

IV. Найдите в тексте антонимы следующих слов:

to increase, little, pure, rarely, usable, approximately; to cool, condensation, to fall, initia1, to condensate, beginning, sooner, gradually

V. Из следующих предложений выпишите сказуемые-синонимы и определите их значения:

1. Solar radiation makes water evaporate from the surface of the ocean. 2. Solar radiation causes water to evaporate from the surface of the ocean. 3. Solar radiation forces water to evaporate from the ocean surface.

VI. Найдите в тексте слова, которые соответствуют следующим словарным определениям:

1)the total measurable supply of water of a11 forms of falling moisture; 2) total precipitation that appears in natural or artificial surface streams

Vll. Расположите следующие существительные в порядке, отражающем бесконечный гидрологический цикл:

runoff; precipitation; evaporation; infiltration and ground water; stream flow; reprecipitation