Today over ninety-eight per cent of our energy comes from fossil fuels; coal, oil and natural gas. But coal and oil are not only fuels. They are also important raw materials for our chemical industries. People now think we should limit their use as fuel, otherwise the worlds supply will soon run out. Consequently, much research is being done into the practical use of the sun for heating buildings. The less fossil fuel we use now, the more we will have for the future.
Solar energy is transmitted from the sunthrough spaceto earth by electromagnetic radiation. It must be converted to heat before it can be used. Various types of solar energy collectors are used to convert the suns radiation to heat. Solar-heated hot water provides not only the buildings hot-water requirements, but space-heating as well. This solar system, based on water-heating, works like this. Each of its collectors, placed on the roof, consists of a shallow fiberglass tray that holds a number of copper tubes under a special glass cover. The tubes are, in turn, fixed to a blackened metal surface which absorbs energy from the sun. The suns rays, passing through the glass, heat the water in the tubes.
Since the energy is available only during the day and only then when there is not a great deal of cloud cover, the heat must be stored. This can be done in water, or in rock or pebble beds. The energy is stored in the hot water in the pipes.
21. Solar energy was first used_______.
A. to start a fire B. to cook food
C. to power a heating-system D. in a war
22. What must be done to solar energy before it can be used?
A. It must be stored in rock beds. B. It must be distilled.
C. It must be converted to heat. D. It must be purified.
23. There is so much research into the use of solar energy because _______.
A. more irrigation projects are needed B. the construction industry is expanding C. fossil fuels are running out D. it transmits electromagnetic radiation
24. Solar energy must be stored because_______.
A. it is limited B. there is not much of it
C. it is not always available D. the passage does not tell us why
25. How many uses has solar energy been put to according to the passage? A. 2. B. 3.
C. 4. D. More than 4.
21. D 22. C 23. C 24. C 25. B
2015年2月的G类雅思写作预测(重点排序)
2015年2月雅思口语的预测 Part 1
2015年3月11日的雅思写作预测
2014年雅思阅读模拟练习及答案(1)
2015年3月G类雅思写作的预测(小作文)
2015年3月1日的雅思考试预测(汇总)
2014年雅思写作的考情分析及2015年备考建议
2014年雅思年度报告:2015雅思口语考试趋势分析
2015年3月1日的雅思口语预测
2015年2月的雅思口语话题预测
2014年雅思年度报告:2015年雅思阅读考试趋势分析
2015年3月8日的雅思阅读预测及备考重点指导
2015年3月的雅思口语预测 Part 1
2015年3月1日d 雅思写作备考重点
2015年3月1日的雅思口语的预测
雅思考试真题
2015年2月的雅思口语最新预测
2015年3月1日雅思口语预测的完整版
2015年4月9日雅思写作的预测
2015年2月的A类雅思写作预测(重点排序)
2015年3月8日的雅思考试口语预测
2015年雅思考试时间
2014年雅思年度报告:2015雅思写作考试趋势分析
雅思口语考试需要注意的六个小细节
2015年4月5日d 雅思写作重点预测(G类大作文)
24个经典的话题沉着应对3月1日雅思口语考试
2015年2月10日雅思听力预测
2015年3月的雅思听力预测
2015年2月1日的雅思写作预测
2015年3月雅思口语的预测 Part 1
不限 |
英语教案 |
英语课件 |
英语试题 |
不限 |
不限 |
上册 |
下册 |
不限 |