Complete the following statements by choosing the answer which you think fits best. Are the other answers unsuitable? Why?

1. Modern civilization is based on metals because:

a) three quarters of all known chemical elements are metals.

b) they can be easily found on the surface of the earth.

c) they are very cheap.

2. Gold has been used for ornaments for thousands of years because:

a) it has beautiful luster.

b) it is not very strong.

c) it is scarce.

3. The process of smelting is used:

a) to make iron harder.

b) to shape metals.

c) to extract metals from ores.

4. Copper began to oust stone because:

a) it could be readily worked to any shape.

b) there was more copper than stone on the surface of the ground.

c) it had a beautiful luster.

11. Agree with the following statements. Prove your reason. Use the expressions: That’s right. It is clear from the text that …

1. Metals are of great importance in our life.

2. Copper has a lot of advantages over stone.

3. The properties of copper change when it is heated.

4. Lead is never found free.

5. Traders helped to spread the art of smelting to other lands.

12. Translate the following sentences. Pay attention to the use of Present Perfect. Find the examples of Present Perfect in the text:

1. Materials Science has become an important subject.

2. Semiconductors have been used to create integrated circuits.

3. Scientists have learnt to investigate properties of materials with the help of new testing methods.

4. This material can withstand vibrations because it has been reinforced.

5. Due to modern technologies a lot of new materials having structures of very small dimensions have been developed.

6. A special testing machine has been used to determine the properties of this metal.

7. The addition of carbon has made steel much stronger than iron.

8. Steel has found wide application in engineering due to its strength and hardness.

13. Look through the text and answer the questions:

1. What helped to broaden the field of metallurgy?

2. What are the three divisions of metallurgy? What do they deal with?

3. Do the processes of working and shaping metals involve chemical changes?

Metallurgy is one of the oldest of arts but one of the youngest of sciences. Many of our metals were known in ancient times, but it is only within the last century or two that the knowledge of the properties of metals has made it possible to apply them in any extended way for industrial purposes.

With the development of physics of metals, metallography, theory of heat treatment and other phases of the science of me­tals, the field of metallurgy has broadened.

Metallurgy in this broader sense falls into three divisions: chemical or extractive, physical and mechanical. Chemical metal­lurgy includes the metallurgical processes involving chemical change and the methods of production and refining.

Physical metallurgy deals with the nature, structure, and phy­sical properties of metals and alloys.

Mechanical metallurgy includes the processes of working and shaping metals — processes which do not involve chemical chan­ges.

Unit 4

1. Memorize the following words:

require obtain feature hammer anvil ductility carry out common tin a great deal of mine liberate molten stiffness durability mercury oxidation bound relatively

требовать получить особенность молоток наковальня податливость выполнить обычный олово много шахта, добывать выделять расплавленный жёсткость долговечность, стойкость ртуть окисление связанный относительно

вимагати отримати особливість молоток ковадло пластичність здійснювати звичайний олово багато шахта, добувати виділяти розплавлений жорсткість довговічність, стійкість ртуть окиснення пов’язаний відносно

1. Practise the reading of the following words:

Require, feature, mercury, durability, hammer, bound, anvil, advance, Egyptians, nuggets, pure, rare, nature, occur, meteor, enough, ore, ancient, oxidation, potential, abundant, edge, weapon, tightly, iron, age, technology, Asia, bound, jewelry.