Classifying materials

Read and translate the text.

Task 1. Translate the following international words before reading the texts.

Learn the vocabulary.

Open the brackets using adjectives in proper form.

1. We should eat (healthy) food. 2. Today the streets aren't as (clean) as they used to be. 3. It's (bad) mistake he has ever made. 4. This man is (tall) than that one. 5. Asia is (large) than Australia. 6. The Volga is (short) than the Mississippi. 7. Which building is the (high) in Moscow? 8. Mary is a (good) student than Lucy. 9. The Alps are (high) than the Urals. 10. This garden is the (beautiful) in our town. 11. She speaks Italian (good) than English. 12. Is the word "newspaper" (long) than the word "book"? 13. The Thames is (short) than the Volga. 14. The Arctic Ocean is (cold) than the Indian Ocean. 15. Chinese is (difficult) than English. 16. Spanish is (easy) than German. 17. She is not so (busy) as I am. 18. It is as (cold) today as it was yesterday. 19. She is not so (fond) of sports as my brother is. 20. Today the weather is (cold) than it was yesterday. 21. This book is (interesting) of all I have read this year. 22. January is the (cold) month of the year. 23. My sister speaks English (bad) than I do. 24. Which is the (hot) month of the year? 25. Which is the (beautiful) place in this part of the country? 26. This good-looking girl is the (good) student in our group.

Bond [bond] – связь Create [kri:'eit] – создавать Creation – создание Due to – благодаря (чему-то) Either – любой Either... or – либо…либо; или…или Employ – использовать Equip [i'kwip] – оборудовать Equipment – оборудование Lattice – решетка Quantity – количество Phenomenon – явление Phenomena (pl) – явления Pure – чистый, без примеси Impure – с примесью Impurity – примесь Relative – относительный

Relatively – относительно Should – следует (совет) It should be added – Следует добавить Similar – подобный Solid – твердое тело; твердый Table – таблица Force n – сила Represent – изображать, представлять State – состояние Perform – выполнять As follows – следующие, как следует ниже Compound – соединение Charge – заряд Particle – частица Readily – с готовностью

Association, centre, characteristic, colleague, conference, contact, cooperation, fundamentals, international, mass, neutron, orbit, proton, reaction, reactor, specialist, sphere, synthetics, system, technician, theory, university, valency = valence;

Biology, geology, medicine, physics;

Characteristic, chemical, electrical, electronic, elementary, experimental, fundamental, official, practical, socialist, theoretical, unique;

Experimentally, fundamentally, officially, practically, theoretically;

Cooperate, orbit, theorize, contact.

There are many ways of classifying materials. The one we shall use here is based on the ability of a material to conduct electricity. It is known that conduction takes place as a result of the motion of charged particles, usually electrons.

The ability of any material to conduct electricity is directly proportional to the number of charged particles inside the material that can be set in motion. Materials (for example metals), that have relatively large numbers of free electrons, readily conduct electric current and are called conductors.

Other materials having very few (or no) free electrons do not readily conduct electric current under normal conditions and are called insulators. It should be realized¹ that the terms 'conductor' and 'insulator' are not absolute, that is² some conductors do not conduct as well as other conductors, while some insulators do not insulate as well as other insulators.

Notes on the text

¹ it should be realized – следует учесть

² that is – то есть

Дата добавления: 2014-12-17