III. Writing Practice

III.1 Make derivatives to complete the sentences.

1. Non-ferrous metals have high electric (conduct), high (corrode), light weight and ease of (form).

2. Wide (accept) of aluminium did not occur until World War II.

3. Aluminium is known to be a white (silver) metal which does not rust in the air.

4. The good electrical (conduct) of the metal makes it suitable for many (apply) in the electrical industry.

5. It is (extensive) used for castings that must be light in weight.

6. Copper was one of the first (engineer) metals.

7. It was used in (history) times for making weapons and tools.

8. Other elements than tin added to copper improve its properties such as (hard) and (resist) to wear.

III.2 Translate into English.

1. Сплавы цветных металлов – это сложные вещества, основным элементом которых являются медь, алюминий или другие цветные металлы.

2. Цветные металлы обладают хорошей проводимостью и устойчивы к коррозии.

3. Самые распространённые металлы этой группы – алюминий, медь, магний, марганец.

4. Некоторые цветные металлы не имеют кристаллической решётки.

5. Вольфрам – самый тугоплавкий метал, а литий – самый лёгкий.

6. Цветные металлы широко распространены в природе, но их трудно добывать и дорого использовать в промышленных целях.

7. Самый распространённый цветной метал – алюминий, а тонна морской воды содержит около 1 кг магния.

8. В основном, цветные металлы используют в электронных приборах, в медицине и как радиоактивные материалы, и в меньшей степени в других сферах.

III.3 Translate the text into Russian in writing. Give the title to it.

Titanium was discovered twice. A British scientist, William Gregor, found it first and called it menachanite, and six years later, in 1977, M.H.Klaproth, a German chemist, also found it and gave it its present name. For many years titanium was of interest only to research chemists – it was considered too brittle to be of any practical value. As it forms compounds easily with rarely every known element, it was the impurities* that made it brittle. The chemists in many countries made endless efforts to isolate titanium in its pure form.

Titanium has one surprising property – it is completely inert in biological media. This metal is extensively used in medical industry. Titanium instruments do not corrode, and are 30% lighter than instruments made of stainless steel. Titanium’s high standard of corrosion resistance, lightness, tensile strength and the ease of forging * and rolling * are finding it more and more uses. A combination of high mechanical properties with a low specific weight and excellent corrosion resistance enables titanium to be used in building supersonic* aircrafts. Titanium alloys are very useful in mechanical engineering and for chemical apparatus. Industrial titanium alloys contain vanadium, molybdenum, aluminium, tin, iron, and other elements, singly or in various combinations.

Vocabulary to the text:

· impurities – примеси;

· forging – ковка;

· rolling - прокат;

· supersonic – сверхзвуковой.

Unit 3

Section I

Conversational topic: “ PLASTICS ”

Дата добавления: 2015-10-30