I. Give all the derivatives of the following words:

To cover, to explore, to direct, to adapt, to situate, to act, to mix, to desire, to use, to vary, to select, to refer, to consist, to repeat, to plant, to separate

II. Find synonyms for fhe following words in the text:

To wish, to have, different, to give, task, better, to combine, well-known, to fit, right, experiment, base, to use, together with, possibility, on condition

III. Translate the text with a dictionary:

I. V. Michurin is known to be a famous selectionist and practical gardener in our country. His scientific tegacy is immense. "We cannot wait for favours from nature. We must wrest them from her"— he used to say. Boldly remaking nature in the interest of man, Michurin evolved more than 300 new varieties of fruits and berries, flowers and decorative plants. Having moved southern plants far to the North he bred new varieties of fruits. For example, Michurin remade the warmth-loving grape, adapting it to the conditions of Leningrad and Kirov, the Moscow area, and many other central and northern regions, where it produces good yields. His efforts made possible fruit cultivation on a large scale in northerly areas and Siberia. Problems of hybridization held an important place in his researches. Studying the complex biological phenomena manifested in hybridization Michurin developed new methods, not known before him either in biological science or in the practical work of plant or animal breeders. Of special significance for biology is Michurin's teaching about the mentor. Its substance consists of the following: if a young plant is to be grafted on an older one, it will acquire the properties of the mentor. The mentor method employed by him helped to breed new remarkable varieties of apples and many other valuable fruits. The subjugating of the forces of nature to the will of man was the idea to which I. V. Michurin dedicated his entire life. This idea lives and triumphs in the deeds of the millions of scientists, and had become the foundation of agriculture in our country.

IV. Translate the text without a dictionary, entitle it and formulate the main idea in one sentence:

Man has been engaged in breeding and selecting plants and animals for thousands of years. During that time he has been able to develop a great many varieties. Breeders are always anxious to increase production. They try to get more and better varieties of berries from each bush, more milk per cow, and more eggs per chicken. In many cases, the breeder has found it possible to develop new varieties that resist high or low temperature and diseases. They use three chief methods in the effort to increase quality and production. These are selection, crossbreading and the use of mutations. The breeder tries most of all to understand the heredity of the animals and plants with which he works. He carries out many experiments to learn about the genes and how they are inherited. Then he tries to get a combination of genes that will give him the qualities he desires. Such experiments may be long, difficult and costly.