Перевести текст, нужно. 20 . the first houses were built for the purpose of protecting their owners from the weather and, therefore, were very simple—a roof to keep off the rain or snow, and walls to keep out the wind. the building erected now can be divided into two broad classifications: they are either for housing or for industrial purpose. as far as the material is concerned, the building can be divided into stone (or brick), wood and concrete types. the brick is an artifical material made of clay then burnt to harden it. the natural stone (rubble masonry) is used for footing and foundations for external walls carrying the load. the buildings made of stone or brick are durable, fire-proof and have poor heat conductivity. the tiers or levels which divide a building into stages or stories are called floors. these may be of timber but in stone buildings they are made of ferro-concrete details in great and small sizes. the coverings or upper parts of buildings constructed over to keep out rain and wind and to preserve the interior from exposure to the weather, are called roofs. these should tie the walls and give strength and firmness to the construction. every building must be beautiful in appearance and proportional in various parts. the interior should be planned to suit the requirements of the occupants while the exterior must be simple without any excesses. any building should be provided with water, electricity, ventilation and heating system. getting water into the house is called plumbing. the plumbers have also to get the water out after it has been used. the first part of this problem is called water supply and the second one is called drainage or sewerage.

darkhun    3   06.08.2019 09:10    6