Exercises

I. Answer the following questions:

1. What proportion (how much) of the total mass of the solar system does the sun contain? 2. In what way does the sun control the planets of the solar system? 3. What is the shape of the planets? 4. The planets are at the same distances from the sun, aren't they? 5. Into what two groups do the planets fall according to their distance from the sun? 6. Which of the planets are larger: the inner or the outer ones? 7. Which of the planets is the largest? 8. Which planet is the smallest one? 9. How large is the sun's radius as compared to that of the earth? 10. In what direction do the planets move around the sun? 11. Do the elliptical orbits in which the planets travel lie in different planes or in nearly the same plane? 12. In what directions do the sun and the planets rotate on (about) their own axes? 13. Do the planets travel along their orbits at the same velocity? 14. What is the relationship between the speed of a planet and the size of its orbit?

Word-Building

II. Give the nouns corresponding to the following verbs:

attract, move, relate, develop, influence, increase, grow, direct, gravitate, except, cause, heat, appear,originate

III. Translate the following sentences paying attention to the singular and plural forms of nouns:

1. axis — axes [ˊæksɪs] — [ˊæksi:z]; analysis — analyses [ənˊælɪsɪs] — [ənˊæləsi:z]

The period of the moon's rotation on its axis is nearly 27¹/₃ days. The pla-nets all rotate about their own axes. Since the internal structure is the most diagnostic character of a mineral, X-ray analysis is one of the most fundamental methods of mineral identification. Analyses of very early gold objects show that their metals always contain impurities such as silver, copper, antimony, and iron, which determine the color.

2. radius — radii [ˊreɪdɪəs] — [ˊreɪdɪaɪ]

The radius of the earth is about four times that of the moon. All the radii of a circle are equal.

3. datum — data [ˊdeɪtəm] — [ˊdeɪtə]

The surface of the ocean is the datum for all topographic and geologic work. These conclusions are based on X-ray analysis data.

4. series — series [ˊsɪəri:z]

Throughout its life history, a stream passes through a series of stages, each with certain definite characteristics. The great series of sedimentary rocks occur in every continent, and tell us much of the world's early history.

Word Study

IV. Translate into Russian paying attention to the word one:

a) Astronomy is one of the oldest of the sciences.

b) 1. This shallow-water zone is one of constant change. 2. There are many hot springs and the hottest ones are in volcanic areas. 3. Near the equator in Africa is a belt which has four seasons, two relatively dry ones, and two wet ones.

c) 1. One must remember that the stars and clouds are in constant motion. 2. On flat land one can easily construct railways and roads. 3. Petrology and structural geology are often so completely interwoven that it is impossible to say whether one is studying a petrological problem by structural methods or a structural problem by petrological methods.

V. Translate into Russian paying attention to the word most:

1. The origin of the earth is the most important and the most difficult question of natural science. 2. Economic geology is a most important branch of geology. 3. We cannot see the true surface of Venus, since the planet's atmosphere acts as a most effective barrier against our telescopes. 4. Volcanoes are distributed over the surface of our planet most unequally. 5. Most volcanoes — over 60 per cent of the total — are concentrated on Pacific coasts and islands. 6. Most of the snow melts in summer but in polar regions and at high altitudes part of it remains throughout the year in glaciers and snowfields. 7. The erosional history of most lands began with emergence of a sea floor. 8. During the Mesozoic [ˏmesoˊzouik] era much of North America was above sea level most of the time. 9. Like the Mesozoic era, the Cenozoic [ˏsi:nəˊzouik] era (Кай­нозойская эра) was a time when most of North America was land.

VI. Memorize the meaning of the words means, mean as they occur in the sentences below: mean (v) «значить, означать»; mean (а) «средний»; means (n) «средство (средства), способ (способы)», by means of «посредством». Translate the sentences into Russian:

1. Deep drilling has been used as a means of investigating the history of the ocean. 2. The means by which waves work are chiefly physical. 3. Movement of the atmosphere in the form of strong wind is an important agency in arid parts of the world, and is, in addition, a leading means of erosion. 4. The mean density of the earth 5.5 means that a cubic foot of average earth-substance weighs about 5.5 times as much as a cubic foot of water. 5. Most minerals can be quickly identified by means of the petrographic microscope.