Exercises. I. Use the following words and phrases in sentences of your own:

I. Use the following words and phrases in sentences of your own:

ferrous metals, steel, cast iron, mould, alloy, pig iron, blast furnace, grey iron, to solidify, foundry, to cast, engineering metals, tool steel, to machine, alloy grey iron, to furnish, malleable iron, to anneal, tensile strength, non-ferrous metals, on account of, grade, to elongate, range, shop.

II. Answer the following questions:

l. What are the main two groups of metals? 2. What elements do ferrous metals consist of? 3. What is the difference between iron and steel? 4. What is casting? 5. What do we call the shop where metals are cast? 6. Why is steel widely used in machine-building? 7. What are the main types of iron castings?

III. State the forms and functions of the ing-forms and translate the following sentences into Russian:

1. Machine-building industry is the leading branch of heavy industry. 2. The work of casting metals is performed in foundries. 3. Metals consisting of iron with some other elements are known as ferrous metals. 4. Engineering metals are used in industry in the

form of alloys because the properties of alloys are much better than those of pure metals. 5. Steel is iron containing from 0.05 to 1.7 per cent carbon. 6. The blast furnace is called so because a blast of hot air is forced into it while producing the pig iron. 7. Malleable iron before annealing is usually called "white iron". 8. For separating iron from impurities the iron ore must be melted at a very high temperature produced by burning coke in a blast furnace.

IV. Fill in the blanks with prepositions because of, of, for, in, with:

1. Metals are... great importance... our life... their useful properties. 2. They are widely used... industrial purposes. 3. There are two large groups... metals: simple metals and alloys. 4. Alloys consist... a simple metal combined... some other elements. 5. Almost all the metals are found... the earth's crust... the form... ores.

V. Translate the following sentences with the predicates in the passive form, then change the predicates into active form:

Example: Metals are usually melted and poured by founders into a form which is called a "mould".

Founders usually melt and pour metals into a form which is called a "mould".

1. Different metals are produced by people in different ways. 2. Three methods are now used by us for producing pig iron. 3. Ferrous metals are used in industry in two general forms such as steel and cast iron. 4. The iron ore charged into the furnace has been melted by the heat produced by the coke burning in the blast of hot air. 5. Malleable iron castings are being increasingly used in industry. 6. Great shock will not be stoodby grey iron. 7. The heat in the electric furnace was produced by electricity.

VI. Find in the text nouns for the following verbs:

to cast, to alloy, to anneal, to compare, to manufacture, to machine, to equip, to produce.

VII. Make up questions to which the italicized words are the answers:

1. Many experiments have been conducted to improve the qualifies of grey iron castings. 2. Some castings require great strength and wearing qualities. 3. Malleable iron castings are much stronger than grey iron castings. 4. Malleable iron can be cast into very large bodies. 5. Metals are usually tested for tensile strength and elongation.

VIII. Translate the following text in written form using a dictionary:

Production of castings made from different metals requires different types of melting furnaces. The cupola furnace is usually used for melting grey iron. The air cupola, and electric furnaces are used to melt the metal for making malleable iron castings. For melting steel, the open-hearth, crucible or electric furnaces are used. Non-ferrous metals are generally melted in crucibles or electric furnaces. The fuels

mostly used for melting metals are coke, coal, oil and gas. Besides the different types of furnaces, different kinds of moulding sand are also required for making the moulds for different metals. -In many cases, it is necessary as well to treat either the metals or the castings in some special way before the castings can be used.

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