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Reading and Speaking

I. Try to answer these questions before you read the text.

  1. What are the most widely used metals in engineering?

  2. What colour are these metals?

  3. What metal is the hardest one: steel, aluminium or copper?

  4. Copper is the heaviest metal, isn't it?

  5. What metal is stronger: aluminium or copper?

  6. What metal is more flexible: copper or steel?

  7. Is aluminium the most or the least flexible metal?

II. Read the text and check your answers.

Steel, copper and aluminium are widely used in engineering. Steel is a grey elastic metal. It is heavier than aluminium, but it is the hardest and the strongest of those three metals. That is why it is widely used for constructing bridges, making tools and car components.

Copper is a red metal. It is harder and stronger than aluminium and more flexible than steel. Electric wires are generally made of copper because this metal has a high electric conductivity. However, copper is the heaviest metal of the three.

The lightest and the most flexible of these materials is aluminium, therefore aircraft, engine components and many kitchen items are made of this metal. Aluminium is a white hard metal.

III. Find the endings of these sentences.

Steel, copper and aluminium are widely used …

Steel is the hardest and the strongest of …

Copper is …

Steel is …

The lightest and the most flexible is …

a red material.

aluminium.

in engineering.

the three metals.

a grey elastic metal.

IV. Complete the sentences.

Different metals … widely … in … . Steel is a grey… metal. It is ... than aluminium. Copper is a red … . Steel is harder and stronger … copper, but copper is … flexible than steel. Copper is the … … . Aluminium is the … flexible material. Steel is … hardest and the … of these three materials.

Activity

I. Ask your groupmate to name the following objects and say what materials they are made of.

Example: ruler / plastic Paul: Look! This is called a ruler. Susan: By the way, what material is it made of? Paul: It is made of plastic. Susan: Why is it made of plastic? Paul: Because plastic is a light material, it is lighter than steel. And it is the least expensive material. Therefore it is used for making rulers.

Objects / materials

  1. a cylinder / steel

  2. a tyre / rubber

  3. a beaker / glass

  4. a wire / copper

  5. a pipe / metal

  6. a tin / aluminium

  7. a shelf / wood

II. Discuss with your partner the following questions.

  1. Why are bridges made of steel, not of copper?

  2. Why are electric wires made of copper, not of plastic?

  3. Why are aircraft made of aluminuim, not of steel?

  4. Why are cutting tools made of steel, not of pure iron?

Writing

I. Study this table and explain why these materials are used for making these things.

Materials

Properties

Application

aluminium

light, soft, corrosion-resistant, highly conductive

engine components, aircraft

copper

heavy, tough, corrosion-resistant, highly conductive

electric wiring, tubing

mild steel (iron with 0.15-0.3% of carbon)

very strong, tough, non-resistant to corrosion

general purposes

high carbon steel (iron with 0.7-1.4% of carbon)

hardest of carbon steels, tough, wear-resistant*

cutting tools (drills, files, saws, etc.)

*устойчивый к износу

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