Exercise 6. Read the text “Composite Materials” and fill the gaps with the following words or phrases: volumes/ conductivity/ properties/ composite/ high/ combinations/
The 1) of two or more different materials are called composite materials. They usually have unique mechanical and physical properties because they combine the best
2) of different materials. Nowadays composites are being used for structures such as bridges, boat-building etc.
Composite materials usually consist of synthetic fibres within a matrix, a material that surrounds and is tightly bound to the fibres. The most widely used type of 3) material is polymer matrix composites (PMCs). PMCs consist of fibres made of a ceramic material such as carbon or glass embedded in a plastic matrix. Usually the fibres make up about 60 per cent by volume.
Composites can also have different properties, such as high thermal or electrical 4) and a low coefficient of thermal expansion.
Although composite materials have certain advantages over conventional materials, composites also have some disadvantages. For example, PMCs and other composite materials tend to be highly anisotropic— that is, their strength, rigidness, and other engineering properties are different depending on the orientation of the composite material. The designer who uses composite materials in structures subjected to multidirectional forces, must take these anisotropic properties into account. Also, forming strong connections between separate composite material components is difficult.
The advanced composites have 5) manufacturing costs. Fabricating composite materials is a complex process. However, new manufacturing techniques are developed. It will become possible to produce composite materials at higher 6) and at a lower cost than is now possible, accelerating the wider exploitation of these materials.

There is a newspaper on the desk. 2. On our street a few new houses. 3. Moya apartment in an old house . 4. pis rary table standing at the window . 5. In this room, a lot of light outside . 6. On the window sills there are no flowers . 7. In the room there is no furniture except chairs. 8. In my room little furniture . 9. This furniture is modern constructions . tion . She is beautiful and easy to use. 10. On the walls are several paintings by contemporary young artists . 11. Chairs standing cro . La in the middle of the room. 12. Above the table alektrichesky light. 13. This low sofa . This sofa is low. 14. bookshelf hanging (located mu) over the sofa . 15. Give me some magazine pozhaluy- Please please Thank you . ( It is not necessary . ) 16. Do not ask the same question . 17. Do you have hot water at home? 18. Send her another letter . 19. Allow me to close the door . 20. Let it us about his new races tale. 21. Tell us the end of the story Ta story has a good ending -We hear

The United States of America is a very diverse country. Its nature, climate, population varies from the East Coast to the west, from the northern border to the southern.Climate is mostly temperate, but tropical in Hawaii and Florida, arctic in Alaska, semiarid in the Great Plains west of the Mississippi River, and arid in the southwest.Natural resources include coal, copper, lead, molybdenum, phosphates, uranium, bauxite, gold, iron, mercury, nickel, silver, tungsten, zinc, petroleum, natural gas, and timber.Natural hazards are a great deal of problems for the USA. Every year, they loose hundred millions of dollars, because of natural hazards. The USA is famous for hurricanes along the Atlantic and the Gulf of Mexico coasts and tornadoes in the Midwest and southeast; mud slides in California; forest fires in the west; flooding.Sometimes there are tsunamis, volcanoes and earthquakes happen. Earthquakes are very often in California.Talking about environment, one should add that air pollution results in acid rains in both the US and Canada. The US is the largest single emitter of carbon dioxide from the burning of fossil fuels.Water pollution from runoff of pesticides and fertilizers takes place here.Climate and Natural Resources.
Климат и природные ресурсы.
Соединенные Штаты — это страна контрастов. Природа, климат, население страны изменяются с восточного побережья на западное, с северной границы на южную.Климат на большей части умеренный, тропический на Гавайях и в штате Флорида, арктический на Аляске, полузасушливый на великих западных равнинах реки Миссисипи и полупустынный на юго-западе.Природные ресурсы включают: уголь, медь, свинец, молибден, фосфаты, уран, бокситы, золото, железо, ртуть, никель, серебро, вольфрам, цинк, нефть, природный газ и древесину.Природные катаклизмы представляют огромную проблему для США. Каждый год страна теряет сотни миллионов долларов из-за природных катаклизмов. США известны своими ураганами вдоль атлантического побережья и побережья Мексиканского залива, торнадо на среднем западе и юго-востоке, грязевыми оползнями в Калифорнии, лесными пожарами на западе, наводнениями.Иногда наблюдаются цунами, вулканы и землетрясения. Очень часты землетрясения в Калифорнии.Говоря об окружающей среде, необходимо добавить, что загрязнение воздуха выливается в кислотные дожди как в США, так и в Канаде. США — самый крупный «производитель» двуокиси углерода от сжигания ископаемого топлива.Имеет место и загрязнение воды из-за сброса пестицидов и удобрений.