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ТОП 10 на сайтеПриготовление дезинфицирующих растворов различной концентрации
Техника нижней прямой подачи мяча.
Франко-прусская война (причины и последствия)
Организация работы процедурного кабинета
Смысловое и механическое запоминание, их место и роль в усвоении знаний
Коммуникативные барьеры и пути их преодоления
Обработка изделий медицинского назначения многократного применения
Образцы текста публицистического стиля
Четыре типа изменения баланса
Задачи с ответами для Всероссийской олимпиады по праву
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ЗНАЕТЕ ЛИ ВЫ?
Влияние общества на человека
Приготовление дезинфицирующих растворов различной концентрации
Практические работы по географии для 6 класса
Организация работы процедурного кабинета
Изменения в неживой природе осенью
Уборка процедурного кабинета
Сольфеджио. Все правила по сольфеджио
Балочные системы. Определение реакций опор и моментов защемления
The First Non - Ferrous Metals
Non-ferrous metals are the metals not composed of or containing iron. As it has been said before, copper was one of the first metals to be used. In its natural form, copper occurs in the ground as copper ore, a mineral. But this ore contains only 0.5 - 1 per cent of the metal. The rest is rock. The world produces 9.6 million tonnes of copper a year. This means that more than a thousand million tonnes of ore have to be removed from the ground and the pure copper extracted.
Most copper is extracted from a compound of iron, sulphur, and copper called sulphide ore. Hot air is blown into a furnace to separate the copper from the iron and sulphur. The iron and sulphur react with the oxygen to form iron oxide and sulphur dioxide, leaving molten copper metal. This copper, known as blister copper, is about 98 per cent pure. A process called electrolysis is needed to separate the remaining impurities. During this process a slab of blister copper is suspended in a solution of copper sulphate and sulphuric acid, where it acts as a positive electrode (anode). When electricity is passed through the solution, the copper in the anode is dissolved. The pure copper collects at the negative electrode (cathode) and the impurities fall below.
Copper is a good conductor of heat and electricity. We use it to make cooling utensils and all sorts of pipes for carrying hot water, both in homes and in industry. We also use it to make different kinds of electrical devices, such as lightning conductors and the electric coils in motors. Copper does not rust easily, so it lasts a very long time.
Such metals as lead and tin were widely known in Roman times. Lead is a soft malleable, ductile, bluish-white, dense metallic element, extracted chiefly from galena and used in containers and pipes for corrosives, in solder and type metal, bullets, radiation shielding, paints and anti-knock compounds.
Some Roman aqueducts still stand today because they were lined with lead and lead does not rust. Many thousands of tonnes were used in a single aqueduct. So much lead was used in water-supply systems that eventually the Romans suffered some lead-poisoning.
Tin was the fifth metal discovered by man. It is a malleable, silvery metallic element obtained chiefly from cassiterite. It is used to coat other metals to prevent corrosion, and forms part of numerous alloys such as soft solder, pewter, type metal and bronze. For example,pewter, an alloy of lead and tin, was widely used in Roman times to make cups and dishes.
Practise after the speaker and learn to pronounce the words given below:
sulphur /’s/\ lf'/; sulphide /’s/\ lfaid/; pure /’pju:э/; electrolysis /ilek’trolisis/; sulphuric /s'l’fju'rik/; cathode /kжрoud/; anode /’ж noud/; galena /g'‘li:n'/; corrosive /k'‘rousiv/; cassiterite /k'‘sit'rait/; pewter /’pju:t'/; aqueduct /’жkwid'kt/.
Exercise 1.Find the English equivalents for the words and word-
combinations given below. Use them in the sentences
of your own.
цветные металлы; содержать железо; извлекать; железо и сера вступают в реакцию с кислородом; электролиз; сляб; анод и катод; электрообмотка; молниеотвод; галенит; припой; гарт; касситерит; предотвратить коррозию; мягкий припой; сплав на оловянной основе; олово; система водоснабжения; ржаветь; акведук.
Exercise 2.Match the English words and word combinations given
below with their Russian equivalents.
1. to be composed of 1. едкое вещество
2. sulphide ore 2. оседать на дно
3. sulphur dioxide 3. состоять из
4. blister copper 4. длиться долгое время
5. fall below 5. электроприборы
6. electrical devices 6. двуокись серы, сернистый ангидрид
7. to last a long time 7. противорадиационный экран
8. corrosive 8. свинцовые отравления
9. radiation shielding 9. покрывать металлы
10. lead-poisoning 10. пузырчатая медь
11. to cover metals 11. серный (железный) колчедан, пирит
Exercise 3.Answer the following questions.
1. What is a non- ferrous metal? 2. What is most copper extracted from? 3. Why is copper so widely valued? 4. Were lead and tin widely known in Roman times? 5. How did the Romans use lead? 6. What are the properties of tin? 7. Why is tin widely used for coating other metals?
Exercise 4. Using English to define.
Aristotle suggested that a good definition should include a general classification of a term plus the specific characteristics that differentiate the term from other members of its class.
Definition formula: Term = Class + Characteristics
In the text given above there are some definitions of tin and lead. Using the pattern put the jumbled words into the right order to make a definition.
1. a process, is, to form, casting, a liquid metal, by pouring, into a
particular shape, into a mold.
2. a mineral, ore, is, can be extracted, a metal, from which.
3. pale-yellow, a, element, sulphur, is, non-metallic.
4. the basis, a star, sun, of, that, is, the solar system, is.
5. uranium, radioactive, metallic, silvery-white, is, heavy, element, easily
6. the, of, environment, is, ecology, study, the.
7. ground, a, on, fog, is, cloud, the, forms, that.
8. the, state, Bavaria, is, largest, southern, the, West Germany, of, in, part.
Exercise 5.Vocabulary in context: Choose the word that best matches
the meaning of the underlined word as it is used in each of
1. Calcium is obtained from the electrolysis of calcium chloride.
a) destroyed b) got
2. The initial research was not successful, so a second experiment was planned.
a) last b) first
3. He wanted to shield himself from the burning sun.
a) open b) protect
4. The space between the earth and the moon is a vacuum.
a) empty b) full
5. The earth absorbs the water from the rain.
a) gives off b) drinks in
6. All efforts were concentrated on the research programme.
a) devoted b) centered
7. Our natural resources are not inexhaustible.
a) limited b) endless
Exercise 6.Give a written translation of the following passages
In some ores the copper is combined with oxygen. In a process called leaching, sulphuric acid is sprayed over these copper oxide ores, which dissolves the copper but not the rock. The copper and sulphuric acid form solution of copper sulphate, which is purified by electrolysis.
Ores contain a mixture of valuable metallic substance and worthless rock. An American schoolteacher, Carrie Everson, invented a way of separating the two in 1886. She ground up ore and mixed it with oil and acid. This produced a froth in which the metallic substances floated while the rocky materials sank.
Focus on Grammar
Modals of Necessity
The modals of necessity are must (which is also used to express strong probability); have to; be to; ought to; should.
Mustexpresses a very strong need:
You must do it.
You must not go there.
Have to expresses need because of certain circumstances:
She is ill and I have to visit her.
Be to expresses a planned or scheduled necessity:
The train was to arrive at 2 o’clock.
Shouldand ought toexpress moderate necessity, sometimes recommendation. These verbs are used to express advice or to make suggestions. They do not change:
You should (ought to) help her to do this work.
In technical instructions shouldis often used to mean ‘must’ (particularly for warnings):
The electricity should be shut off.
Exercise 1.Insert the verb to be (to) or to have (to) in the necessary tense-form.
1. It looks like raining. 2. You … to take your raincoats. 3. We …to leave Moscow on Monday. 4.You not …to tell them about it if you don’t want to. 5.I did not expect that the worst …to happen. 6.You not …to discuss this problem with him before you get all the necesary instructions. 7.This very evening I … to dine with a gentleman whom I have never met before. 8.Stay here while he is busy. I don’t think you’ll …to wait long.
9. We …to work hard to achieve good results. 10. It was getting pretty late, and I …to leave in order not to be late for the last bus. 11. I did not know who …to be my roommate. 12. He …to leave for Bath that night but suddenly changed his plans. 13. He said you would …to go there alone. 14.The order came that we … not to leave the village before night. 15. Remember that you … to be at his place not later than ten.
Exercise 2.Fill in the blanks with the modal verbs expressing necessity.
1. He was disappointed because he . . . get up at 6 o’clock. 2. I have invited my friends for lunch. They . . . come at one o’clock. 3. You . . . make any noise after 11 o’clock. 4. Peter, you . . . clean your own boots. 5. I . . . be at the station at ten. It is very important. 6. You . . . eat between meals; it will make you fat. 7. I’m afraid I . . . go now. I . . . to meet Mother at the station. 8. It is very late. You . . . phone them now. 9. The situation was very dangerous. He felt that something . . . to be done. 10. You . . . eat so much bread; you will gain weight. 11. We . . . to leave on Friday. 12. Nobody met me when I came. I . . . to arrive by the ten o’clock train, but I couldn’t get a ticket, so I was late. 13. Why . . . I suffer? What have I done? 14. It was too late to change the plan, and it . . . to remain as it was.
Exercise 3.Translate the following sentences into Russian.
Explain the use of the modals.
1. You must have a visa in your passport to visit Britain. 2. I promised I’d be on time, I mustn’t be late. 3. Yesterday I was to meet her at the station at three o’clock but the train was late. 4. You ought to ask somebody for advice. It is a very difficult problem to solve it alone. 5. You haven’t got much time, you must hurry. 6. I think you should accept this job. 7. You must stop smoking. 8. You should stop smoking. 9. It is a really good play. You ought to go and see it. 10. She had to move to another appartment because she hadn’t enough money to pay for the old one. 11. I am sure they shouldn’t get married. They are too different. 12. Do you really have to do all this work about the house? Yes, I’m afraid I have to because my husband is too busy at his work and comes back late at night.
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