17. Your friend wanted to do a lot of things at the practical class yesterday. Ask him if he was allowed to do all of them.

For example:

• to demonstrate the new applications of steels

A: Were you allowed to demonstrate the new applications of steels?

B: No, I wasn’t. But I will be allowed to do it tomorrow.

To work in the rolling mill; to test the performance characteristics of alloy steels; to use a new milling machine; to study the structure of stainless steels; to observe how steel is cast.

18. Discuss with your friend which of these things may be done.

For example:

• machine tools / to be made of pig iron

1. May machine tools be made of pig iron?

2. Certainly they may. They may be made of pig iron.

or B. I’m afraid they may not. They may not be made of pig iron.

1. pure iron / to be refined

2. the properties of iron / to be modified easily

3. the carbon content of steel / to be varied

4. hydrogen / to be added to alloy steel

5. steel / to be tempered

6. steel alloys / to be protected from corrosion

7. steel / to be used for electrical wiring

8. machine tools / to be made of pure iron

19. Translate the following sentences from Russian into English.

1. В качестве электрического проводника мы можем использовать медь.

2. Мы смогли изучить свойства алюминия на практических занятиях.

3. Преимущество меди в том, что её можно перерабатывать несколько раз.

4. Вчера на практическом занятии мы должны были провести эксперимент с мультиметром.

5. Мы не можем сравнить свойства этих элементов.

6. Вы не могли бы объяснить мне как добывается медь?

7. Могу ли я использовать эти элементы для эксперимента?

8. Студенты должны сравнить результаты двух экспериментов.

9. Медные сплавы могут быть использованы в разных отраслях промышленности.

10. Бронза может оказывать сопротивление коррозии.

20. Choose as many words from the table оf ex. 1 as you can and form sensible, using Modal Verbs.

For example:

• We can alloy copper with aluminium.

Specialist Reading

21. Read the text ‘Copper’ only once. How much can you remember? Answer these questions without additional reading.

1. Is copper the oldest metal that is known to man?

2. What properties does copper possess?

3. What is bronze?

4. When, where and why did bronze appear?

5. What are the applications of copper and its alloys?

6. Why aren’t we afraid of working out the resources of copper?

If you failed try to answer these questions again after doing the exercises given below the text.

Copper is man’s oldest metal as people could extract it more than 10.000 years ago. As it is rather soft and ductile, copper is alloyed with other elements. There is evidence that the first copper alloy – bronze (90% copper, 10% tin) – was produced around 2800 BC in countries such as India, Egypt and Mesopotamia. Bronze was harder and could be used for making reliable cutting tools. Its use characterizes the Bronze Age.

The workability and the ability for corrosion resistance made copper, bronze and brass the most important functional as well as decorative materials from the Middle Ages and on till the present day. With the beginning of the Electrical Age the demand for copper increased tremendously because it is an unusually good conductor of electricity and heat. Today more than 5 million tons of copper are produced annually and the copper metals are playing an increasingly vital part in all branches of modern technology.

The good news is that we will not run out of copper. The worldwide resources of this important and valuable metal can be estimated at nearly 5.8 trillion pounds of which only about 0.7 trillion (12%) have been mined throughout history. Besides, nearly all of 700 billion pounds is still in circulation because copper’s recycling rate is higher than that of any other engineering metal. Each year nearly as much copper is recovered from recycled material as is obtained from newly mined ore. Almost half of all recycled copper scrap is old post-consumer scrap, such as discarded electric cable, junked automobile radiators and air conditioners, or even ancient Egyptian plumbing! The remainder is new scrap, such as chips and turnings from screw machine production. Engineers hope that we will be able to use copper for centuries on.

22. Read the text again and complete the sentences.

1. Today more than 5 million tons of copper are …

2. As it is rather soft and ductile, copper is …

3. ... was produced around 2800 BC in countries such as India, Egypt and Mesopotamia.

4. With the beginning of the Electrical Age the demand for copper …

5. … recovered from recycled material as is obtained from newly mined ore.

6. . Engineers hope that …

7. Copper is man’s oldest metal as people could …

8. … could be used for making reliable cutting tools.

9. Today more than 5 million tons of copper are …

10. … because copper’s recycling rate is higher than that of any other engineering metal.

23. Match the terms in Table A with their definitions in Table B

Table A

1. copper

2. bronze

3. alloy

4. corrosion

5. brass

Table B

1. a very hard bright yellow metal that is a mixture of copper and zinc

2. a metal that consists of two or more metals mixed together

3. the gradual destruction of metal by the effect of water, chemicals etc

4. a soft reddish metal that allows electricity and heat to pass through it easily and is used to make electrical wires, water pipes etc

5. a hard metal that is a mixture of copper and tin.