- UID
- 550083
- 在线时间
- 小时
- 注册时间
- 2010-7-26
- 最后登录
- 1970-1-1
- 主题
- 帖子
- 性别
- 保密
|
第一篇的第4题 和第13题
The burning of fuel, such as by cars, is not the only source of this increased heat. Two other factors contribute to the higher overall temperature in cities. The first is the heat capacity of the materials that constitute the city, which is typically dominated by concrete and asphalt. During the day, heat from the Sun can be conducted into these materials and stored—to be released at night. But in the countryside materials have a significantly lower heat capacity because a vegetative blanket prevents heat from easily flowing into and out of the ground. The second factor is that radiant heat coming into the city from the Sun is trapped in two ways: (1) by a continuing series of reflections among the numerous vertical surfaces that buildings present and (2) by the dust dome the cloudlike layer of polluted air that most cities produce. Shortwave radiation from the Sun passes through the pollution dome more easily than outgoing longwave radiation does; the latter is absorbed by the gaseous pollutants of the dome and reradiated back to the urban surface.
4. According to paragraph 3, each of the following contributes to making urban areas warmer than the surrounding countryside EXCEPT
○the fuel burned by motor vehicles
○how well the house is insulated
○the easy flow of heat into the ground in city areas covered by vegetation
○the repeated reflection of solar radiation back and forth among buildings
这b根本是第二段讲得内容啊！为毛不选b！
Paragraph 4: Cities, then, are warmer than the surrounding rural areas, and together they produce a phenomenon known as the urban heat island. Heat islands develop best under particular conditions associated with light winds, but they can form almost any time. ■The precise configuration of a heat island depends on several factors. ■For example, the wind can make a heat island stretch in the direction it blows. ■When a heat island is well developed, variations can be extreme; in winter, busy streets in cities can be 17℃ warmer than the side streets. ■Areas near traffic lights can be similarly warmer than the areas between them because of the effect of cars standing in traffic instead of moving. The maximum differences in temperature between neighboring urban and rural environments is called the heat-island intensity for that region. In general, the larger the city, the greater its heat-island intensity. The actual level if intensity depends on such factors as the physical layout population density, and productive activities of a metropolis.
13. Look at the four squares [■] that indicate where the following sentence could be added to the passage
Another possibility is for the heat island to be stretched along the course of major rivers, since large waterways typically have a warming effect on the air directly above them.
Where would the sentence best fit?
还有13题 我觉得很迷茫 我选了b 觉得c不对 应该是for example在 another possibility后面 |
|
京公网安备11010202008513号 京ICP证101109号 京ICP备12012021号
发表于 2011-9-23 13:16:12
收藏
收藏
楼主
