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IV. Translate from Russian into English using the vocabulary of the Unit.

    1. Способность вещества оказывать сопротивление проходу тепла, электричества и звука имеет большое значение.

    2. Теплопроводность сухой древесины довольно низкая. Вот почему она широко используется в строительстве и производстве электроприборов.

  1. Очень плотная тяжелая древесина производит тепло быстрее, чем легкая пористая.

  2. Зеленая сырая древесина проводит тепло быстрее и лучше, чем сухая, т.к. вода, содержащаяся в ней является более хорошим проводником, чем воздух.

  3. Сухая древесина содержит значительный объем воздуха в своих клетках.

  4. Древесина обладает отличными изоляционными качествами.

  5. Облицовка комнат древесиной значительно снижает потерю тепла.

  6. Благодаря тому, что древесина плохо проводит тепло, ее используют в конструкциях огнестойких дверей.

  7. Хорошо изготовленная дверь из массивной древесины может сопротивляться проходу тепла долгое время.

  8. Документы в металлическом картотечном шкафу скорее обуглятся, чем в деревянном во время короткого пожара.

V. Speak about.

1. The importance of heat conductivity of wood.

Unit 3

Gerund

Grammar:

Species of Trees and Their Application

  1. Answer the questions:

    1. What species of trees do you know?

    2. What is the difference between hardwoods and softwoods?

    3. What species grow in our region?

        1. Read the text and try to understand it.

In our rapidly changing cosmic age wood continues to serve mankind in different ways. In spite of many artificial materials having been created we

still depend on wood and articles made of wood. If wood disappeared suddenly life would change greatly. How would our houses be furnished without umber and veneer? Where should we get political, cultural and scientific information if there were no books and newspapers?

Raw materials from which lumber is produced are logs of definite quality and size, belonging to different forest species. The logs are usually divided into three grades, the first two being used for high quality lumber.

An engineer of wood-working industry should know how to use wood in construction as well as for decorative purposes to the best advantage. Usually the valuable species are not used for making the bodies of articles. The articles made of valuable species would be too heavy and too expensive. So the body of an article is often made of cheap species and all the facing parts are covered with veneer of valuable species.

Different softwoods and hardwoods are used in cabinet making, beginning with the cheapest local species to the valuable expensive and rare ones. Many of them possess such properties as high durability, attractive colour and pleasant odour.

Pine being light in weight, cheap and available in many localities makes it especially suitable for cabinet making. Its being knotty, resinous and hard for finishing is considered to be allowable defects. Doors, kitchen tables, banks and stools are usually made of pine.

Due to walnut possessing attractive grain figure it is used for decorative purposes chiefly as veneer. Besides it has high density and possesses great adaptability to high quality finishing.

Oak, beech and mahogany are also mostly used for decorative purposes.

General understanding

Answer the questions:

    1. Does wood serve mankind in different ways?

    2. What articles made of wood can be found in every house?

    3. What might happen if wood disappeared suddenly? Why?

    4. What is the raw material for lumber?

    5. What should every engineer of woodworking industry know?

    6. What species are usually used for making the bodies of the articles?

    7. Why aren’t valuable species used for this purpose?

    8. How are valuable species used?

    9. What properties do many softwoods and hardwoods possess?

    10. Where is pine used? Why?

    11. What defects in pine are considered to be allowable?

    12. What is walnut distinguished for? What is it used for?