Лекция: Distance from the sun
The annually changing distance of the earth from the sun produces seasonal variations in our receipt of solar energy. Owing to the eccentricity of the earth's orbit around the sun, the receipt of solar energy on a surface normal to the beam is 7 per cent more on 3 January at the perihelion than on 4 July at the aphelion. In theory (that is, discounting the interposition of the atmosphere and the difference in degree of conductivity between large land and sea masses), this difference should produce an increase in the effective January world surface temperatures of about 4 °C, over those of July. It should also make northern winters warmer than those in the southern hemisphere, and southern summers warmer than those in the northern hemisphere. In practice, atmospheric heat circulation and the effects of continentality substantially mask this global tendency, and the actual seasonal contrast between the hemispheres is reversed. Moreover, the northern summer half-year (21 March-22 September) is five days longer than the southern hemisphere summer (22 September-21 March). This difference slowly changes; about 10,000 years ago the aphelion occurred in the northern hemisphere winter, and northern summers received 3-4 per cent more radiation than today. This same pattern will return about 10,000 years from now.
Упражнение 8.
Выберите из текста Distance from the sun 10–15 основных,
с точки зрения смысловой нагрузки, слов (ключевые слова). Определите, к каким частям речи они относятся.
Упражнение 9.
В каждом предложении текста Distance from the sun найдите подлежащее и сказуемое. Определите время и залог сказуемого.
Упражнение 10.
Переведите текст письменно.
(Контрольное время – 25 минут)