V. Ответьте на вопрос: What do the properties of metals depend on? контрольное задание №2 (Вариант 4) (“ав”, “им”)

I. Перепишите следующие предложения; подчеркните в каждом из них глагол-сказуемое и определите его видо-временную форму и залог. Переведите предложения на русский язык. В разделе (б) обратите внимание на перевод пассивных конструкций.

а) 1. . Thousands of researchers and scientists have taken part in the conference.

2. They are still looking for the suitable material for this purpose.

б) 1. Synthetic rubber products were developed between 1914 and the 1930s.

2. Many compounds can be decomposed when they are acted upon by different forms of energy.

II. Перепишите следующие предложения; подчеркните Particle I и Particle II и установите функцию каждого из них, т.е. укажите, является ли оно определением, обстоятельством или частью глагола-сказуемого. Переведите предложения на русский язык.

1. Natural rubber is a thermoplastic material that becomes soft when heated and hard when cooled.

2. Matter composed of any chemical combination of elements is called a compound.

3. The machine-tool having some suitable for them characteristics required special lubricant.

4. To achieve a device with desired service life the engineers spent 2 years.

III. Перепишите следующие предложения; подчеркните в каждом из них модальный глагол или его эквивалент. Переведите предложения на русский язык.

1. These metal parts had to be subjected to X-ray examination.

2. You may use this device to analyze its exact composition.

3. These new materials should to withstand much higher temperatures than the metals.

4. Ethylene gas can be obtained by cracking petroleum.

IV. Прочтите, перепишите и переведите.

METALS

Metals are materials most widely used in industry because of their properties. The separation between the atoms in metals is small so most metals are dense. The atoms are arranged regularly and can slide over each other. That's why metals are malleable and ductile. Metals vary greatly in their properties. For example, lead is soft and can be bent by hand, while iron can only be worked by hammering at red heat.

The regular arrangement of atoms in metals gives them a crystalline structure. Irregular crystals are called grains. The properties of the metals depend on the size, shape, orientation, and composition of these grains. In general, a metal with small grains will be harder and stronger than one with coarse grains.

Heat treatment such as quenching, tempering, or annealing controls the nature of the grains and their size in the metal. Small amounts of other metals (less than 1 per cent) are often added to a pure metal. This is called alloying and it changes the grain structure and properties of metals.

All metals can be formed by different metalworking processes, but some require hot-working. Both metal fatigue (усталость металла) and creep (ползучесть) are taken into account by engineers when designing, for example, airplanes, gas-turbines, and pressure vessels for high-temperature chemical processes. The ways of working a metal depend on its properties.

dense - плотный

grains - зерна

coarse- грубый, крупный

alloying - легирование

quenching - закалка

tempering - отпуск после закалки

annealing - отжиг, отпуск