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

oxidized, a.

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

the sentences.

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

Leaching

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.

Carrie Everson

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.