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

1. In. many experiments one should, check the temperature 6f the substance being heated.

2.1 think that the group of specialists will be able to carry out the task.

3: When given in greater amounts certain medicines can affect the biological functions of the body.

4. Before entering the chemical laboratory we must put on white gowns.

9. Переведите предложения.

1. Усердная работа приведет к успеху.

2. Кто планирует это научное исследование?

3. Студенты посещают лекции и практические занятия по химии.

10. Прочитайте и письменно переведите тек­ст.

Пояснения к тексту

with, the exception... за исключением

it follows that in most instances... следует, что в большинстве случаев...

is of interest primary because of... представляет интерес в основном из-за...

there were theoretical grounds for для такого мнения были теоретические обоснования

this opinion

as a matter of fact между прочим

Alicyclic Compounds.

Garbocyclic compounds are classified on the basis of their behaviour as aromatic or alicyclic. With the exception¹ of cyclopropane to be generally regarded as the first member of the cycloalkane series and its derivatives, the alicyclic compounds possess chemical properties very similar to those of the aliphatic series.

It follows that in most instances² our knowledge of aliphatic compounds can be transferred to the members of the alicyclic group. On this account the chemistry of alicyclic compounds is of interest primary because of³ stereochemical properties inherent in the ring form as opposed to open chain structures. The chemical manifestation of space factors in this field are most pronounced in connection with reactions which involve the opening and closing of rings, and in the alteration of properties on functional groups which are a part of the rings or are directly attached to it.

Cyclohexane and its derivatives can be made by the addition of hydrogen to the corresponding aromatic compounds and, for reason, they have been called hydroaromatic compounds. It is possible to prepare aromatic compounds also by dehydrogenation of the corresponding cyclohexane derivatives. However, this relationship of the cyclohexane group to the aromatic series is almost entirely a genetic one; the two classes differ radically in their chemical properties.

This close connection between aromatic and alicyclic compounds is undoubtedly responsible for the fact that of the letter group, the six member type was the first to be prepared. Indeed, until about 1880 it was generally supposed that rings smaller or larger than this could not exist. All attempts to synthesize such rings had been fruitless, and they had not been found in nature. Moreover, there were theoretical grounds for this opinion⁴, for it was evident that the smaller rings, at least, could not be made from carbon atoms having the rigid tetrahedral form which had been used so successfully in solving other structural problems.

If the four bonds of a carbon atom arc directed toward the vertices of a regular tetrahedron, each forms an angle of 109° 28' with the others. As a matter of fact⁵, it is impossible by use of such atoms to construct any ring of fewer than five members.

Between 1880 and 1885 came a rapid succession of events which revolutionized chemist's ideas of ring compounds and laid the foundations of modem alicyclic chemistry.

ВАРИАНТ 5

1. Перепишите следующие предложения. Определите по грам­матическим признакам, какой частью речи являются слова, оформ­ленные окончанием s, и какую функцию это окончание выполняет.

Переведите предложения на русский язык.

1. I had some good ideas how to complete the experiment.

2. Last month my friend read a very interesting book on our region's history.

3. The inhabitants of Volgograd are fond of their city.