Тест
control yourself
1. high cost and low fire-resistance are classified as
a.advantages of construction materials.
b.disadvantages of construction materials
2. cement, brick, and concrete may serve as examples of
a.natural materials
b.artificial materials
3. durability, strength, and high fire-resistance are properties
a.of stone
b.of wood
4. iron, steel, and their alloys belong to
a.ferrous metals
b.non-ferrous metals
5. one of the advantages of cast iron is
a.its cheapness
b.its high cost
6. aluminum is
a.a good conductor of electricity
b.a poor conductor of electricity
7. wood is considered to be
a.the only naturally renewable material
b.one of the naturally renewable materials
8. in cut wood water content is
a.constantly increasing
b.constantly decreasing
9. steel, brick, and concrete
a.differ in their properties
b.have the same structural properties
10. the drier is the cut wood
a.the lower is its strength
b.the greater is its strength
11. large structural members are produced by glueing together
a.large strips of wood
b.small strips of wood
12. wood panels are
a.much easier to install than boards
b.much more difficult to install than boards
13. plywood panels are made up of
a.thin wooden veneers glued together
b.thick wooden veneers glued together
14. timber is material that is
a.artificially renewed
b.naturally renewed
15. removal of moisture from timber
a.increases its strength, hardness, and workability
b.decreases its strength, hardness, and workability
16. birch and oak belong to
a.hardwoods
b.softwoods
17. hardwoods are widely used
a.for sanitary purposes
b.for decorative purposes
18. in ancient egypt bricks were produced
a.by burning
b.by drying in the sun
19. russia is
a.poor in raw materials
b.extremely rich in raw materials
20. overburned brick
a.should not be used in construction
b.can be used for construction purposes
21. underburned brick is
a.highly porous
b.glass hard
22. bricks are produced of
a.sand and water
b.mortar and burned clay
23. many/few growing forests serve for producing
a.much timber
b.little timber
24. the properties of building materials
a are of no importance for building purposes
b.should be taken into account
25. ceramic tiles are
a.modern products
b.ancient products
26. world's modern atmosphere is
a.clean and fresh
b.highly polluted by chemical waste
27. the colour of ceramic tiles
a.does not depend on the colour of clay
b.depends on the colour of the clay they are made up of
28. ceramic tiles are applied by means of
a.glue
b.some adhesive substance
29. they are applied with an extremely
a.thin mortar joint
b.thick mortar joint
30. the properties of terracotta are
a.different from the properties of brick
b.similar to the properties of brick
развивающаяся на лишенных жизни территориях — скалах, обрывах, наносах рек, сыпучих песках, застывшей лаве и др. При заселении таких участков живые организмы за счет своего метаболизма изменяют условия проживания и сменяют друг друга. Основная роль принадлежит накоплению отмерших остатков растений и продуктов разложения. Это зависит от характера растительности и от комплекса разрушающих её микроорганизмов, грибов и животных. Постепенно формируется почвенный профиль, изменяется гидрологический режим участка, микроклимат. Такие сукцессии называются в геоботанике — экогенетическими, так как ведут к преобразованию самого местообитания. Процесс первоначального формирования растительного покрова называется также сингенетической сукцессией[1].