вар 3 characteristics of concrete

ВАРИАНТ 3
        I. Переведите следующие предложения на русский язык    
    1. If you don’t know some words, you may use a dictionary.
2. A number of electrons the atom loses or receives is called its valence.
    3. The first railroad in Russia was the railroad which connected Moscow with St. Petersburg.    
      4. The information science gets about other galaxies comes through radiotelescopes.
     5. The universities provide a wide range of courses for those who want to get higher-level posts in commerce, industry and administration.
    6. They learned to make papyrus, which they used especially for writing and for drawing.

II. Translate the sentences
1. Introducing new methods into practice requires much time.
2. In converting water into ice we do not change its composition.  
3. Nowadays computers capable of performing billions of operations a second are required.
    4. By subjecting air to very great pressure and cooling it is possible to transform it to the liquid state.  

III. Переведите предложения на русский язык, обращая внимание на функции глагола to HAVE
1. The engineers have to study the problem of using cosmic rays.
2. The book has many diagrams.
3. We have to do this work in time.  
4. They have built the bridge recently.

IV. Переведите предложения на русский язык, обращая внимание на разные значе¬ния слова THAT
1. That the Earth is round was unknown for a long time.  
2. The problems of water supply in this city are as important as those of lighting.
3. The simplest materials are those which have only one kind of atoms.  
4. The cities that were destroyed during the war were reconstructed.  
V. Переведите предложения, обращая внимание на различные значения AS
1. As the train was approaching the station we went to the platform.    
2. The teacher as well as her students is going to the theatre.  
3. Specialists do not use solar cells in industry as they are too expensive.  
VI. Прочитайте и письменно переве¬дите текст  The characteristics of concrete
The characteristics of concrete depend upon the quality of the materials used, grading of the aggregates, proportioning and amount of water. The most important requirements for concrete are: it should be hard, strong, durable, fire-resistant and economical.
Concrete can be divided into two classes: mass or plain concrete and reinforced concrete (ferro-concrete) where it is necessary to introduce steel. Plain or mass concrete can be used for almost all building purposes. Ferro-concrete is used in building bridges and arches, dams and dock-walls, for structures under water, for foundations, columns, girders, beams.
Builders now produce two types of new building materials: alkali-slag concrete and silica concrete.
In alkali-slag concrete cement is replaced by a mixture of granulated blast-furnace slags and sodium and potassium compounds. The fillers can be sand or sandy loams. The new material is now being used for irrigation systems, roads, pavements and other structures.
Silica concrete is light, fire-resistant and acid-proof. It contains no cement whatever. Silica concrete is widely used in aviation and in under water constructions.
           VII. Прочтите 1 абзац текста и ответьте на следующий вопрос:
Where is the alkali-slag concrete used?