I. Translate the following words bearing jn mind the meaning of the affixes and memorize them:

1. to magnify (v), magnifier (n), magnification (n)

2. to increase (v), increase (n), increasing (adj), increasingly (adv)

3. to decrease (v), decrease (n)

4. to inspire (v), inspiration (n)

5. to graduate ((v), gradual (adj), gradually (adv)

6. to extend (v), extention (n), extensive (adj), extensively (adv)

7. to explore (v), explorer (n), exploration (n), explorative (adj)

8. vision (n), visionary (n) (adj), visibility (n), visible (adj)

9. to observe (v), observer (n), observatory (n), observant (adj), observance (n)

10. to reflect (v), reflector (n), reflection (n), reflective (adj)

11. to invent (v), inventor (n), invention (n), inventive (adj)

12. to appear (v), appearance (n) to disappear (v), disappearance (n)

II. Read the following words and guess their meaning:

Sphere, decade, lens, position, telescope, astronomy , fact, visual, professional, limit, object. bacteria (pb). Cappilary, sperm, instrument, reflector, platform. Illustrate, film.

III. State to what part of the speech the words belong and translate them into Russian; form the corresponding verbs:

Difference, assimilation, respiration, reproduction, organization, movement, magnification, resemblance, relation.

IV. Form the nouns corresponding to the following verbs:

To discover, to construct, to affect, to know, to develop, to vary, to divide, 'to differ, to resemble, to observe, to suggest, to apply, to encourage, to agree, to magnify, to appear.

V. Underline the prefixes in the following words and translate them:

To discover, invisible, unknown, to exclude, indifferent, unnatural to mislead, impossible, independent, irregular, nonliving, disorder; illegal.

VI. Translate the following sentences into Russian paying attention to the emphatic construction "it is... that";

1. It was the electron microscope that finally revealed them as objects that could be seen.

2. It is the absence of vitamins that brings on diseases.

3. It is very important to begin the experiment in time.

4. It is the magnifying power of lenses that made it possible to see tiny things.

5. It was Carolous Linneus who suggested the first system of classification of living things.

6. It is necessary to use only very thin objects to see them under the microscope.

7. It was the new method of investigation that helped to finish the work so successfully.

8. Anton von Leeuwenhoek was the first man who penetrated through his lenses into'the world of the microscope.

VII. Translate the text into Russian and then back into English, compare your version wifh the original:

In science one of the most important discoveries having a great influence on the development of science was the fact that microscope has come into common use among scientists. The microscope gave scientists new power. Now they could see things that had been hidden. The first microscopes were very simple. They had only single lenses, some had double lenses with a tube between them. Anton von Leeuwenhoek was the first man who penetrated through these lenses into the mysterious world of the microbe. No one before his time had guessed that such tiny organisms existed.