A. CHILLED B. DECENT C. MEAGER D. JUNK II. READING. PART A...

15. A. chilled B. decent C. meager D. junk II. READING. PART A. READ THE PASSAGE AND CHOOSE THE BEST ANSWERS TO THE QUESTIONS. The radical change in the land's surface that results when rural areas are transformed into cities is a significant cause of the rise in temperature in cities that is known as urban heat island. First, the tall buildings and the concrete and asphalt of the city absorb and store greater quantities of solar radiation than do the vegetation and soil typical of rural areas. In addtton, because the concrete and asphalt are impermeable, the runoff of water fdowing a rain is rapid, resulting in a severe reduction in the evaporation rate. So heat that once would have been used convert liquid water to a gas goes instead to increase the surface temperature further. At night, although both city and countryside cool through radiation losses, the stone-1ike surface of the city gradually releases the additional heat accumulated during the day, keeping the urban air warmer than that of the outlying areas. Part of the urban temperature rise must also be attributed to waste heat from such sources as home heating and air conditioning, power generation, industry, and transportation. Many studies have shown that the magnitude of human-made energy in metropolitan areas is equal to a significant percentage of the energy received from the Sun at the surface. Investigations in Sheffield, England, and Berlin showed that the annual heat production in these cities was equal to approximately one-third of that received from solar radiation. Another study of the densely built-up Manhattan section of New York City revealed that during the winter, the quantity of heat produced from combustion alone was two and one-half times greater than the amount of solar energy reaching the ground. In summer, the figure dropped to one-sixth. It is interesting to note that during the summer there is a mutual reinforcement between the higher nighttime temperatures of the city and the human-made heat that helped create them. That is, the higher temperatures result in the increased use of air-conditioners, which, in turn, use energy and further increase the amount of urban heat. During the winter the nighttime warmth of urban areas, produced in large part by heavy energy consumption, is beneficial because less energy needed to heat buildings.