Question

At the moment, there are two reliable ways to make electricity from sunlight. You can use a panel of solar cells to create the current directly, by liberating electrons from a semiconducting material such as silicon. Or you can concentrate the sun’s rays using mirrors, boil water with them, and employ the steam to drive a generator.
Both work. But both are expensive. Gang Chen of the Massachusetts Institute of Technology and Zhifeng Ren of Boston College therefore propose an alternative. They suggest that a phenomenon called the thermoelectric（热电）effect might be used instead—and they have built a prototype（原型）to show that the idea is practical.
Thermoelectric devices are not new. They are used, for example, to capture waste heat from car engines. They work because certain materials generate an electrical potential difference within themselves if one part is hotter than another. That can be used to drive a current through an external circuit.
The reason thermoelectric materials have not, in the past, been applied successfully to the question of solar power is that to get a worthwhile current you have to have a significant temperature difference. (200℃ is considered a good starting point.) In a car engine, that is easy. For sunlight, however, it means concentrating the heat in some way. And if you are going to the trouble of building mirrors to do that, you might as well go down the steam-generation route, which is a much more efficient way of producing electricity. If the heat concentration could be done without all the equipment of mirrors, though, thermoelectricity’s inefficiency would be balanced by the cheapness of the equipment.
In their view, three things are needed to create a workable solar-thermoelectric device. The first is to make sure that most of the sunlight which falls on it is absorbed, rather than being reflected. The second is to choose a thermoelectric material which conducts heat badly but electricity well. The third is to be certain that the temperature gradient（梯度）which that badly conducting material creates is not wasted by poor design.
【小题1】The following methods can be adopted to make electricity from sunlight EXCEPT         .

A．putting a panel of solar cells into use

B．concentrating sun’s rays with mirrors

C．creating a solar-thermoelectric device

D．building a practical solar prototype

【小题2】Why was the application of thermoelectric materials a failure in the past?

A．Because it’s hard for them to build enough mirrors to make it work.

B．Because 200℃ was hard to reach at that time even in a car engine.

C．Because of the failure of having a significant temperature difference.

D．Because it was hard to focus the sun’s rays with equipment of mirrors.

【小题3】Which of the following is the best title for this passage?

A．Thermoelectric Device --- the Best Method of All

B．A New Method of Making Electricity from Sunlight

C．How to Create a Workable Thermoelectric Device

D．Solar Power --- a New Energy Trend in the Future

Answer 1

【小题1】D
【小题2】C
【小题3】B

解析试题分析：传统的太阳能发电设备都很贵，这篇文章介绍的是太阳光发电的一个新的方法，既可以有效的发电，也可以节约设备的开支。
【小题1】细节题：从第一段的句子：You can use a panel of solar cells to create the current directly, by liberating electrons from a semiconducting material such as silicon. Or you can concentrate the sun’s rays using mirrors, 可知用太阳能发电，可以用太阳能光板，用镜子，也可以用太阳能热点技术，没有提到D项。
【小题2】细节题：从第四段的句子：The reason thermoelectric materials have not, in the past, been applied successfully to the question of solar power is that to get a worthwhile current you have to have a significant temperature difference. (200℃ is considered a good starting point.) 可知以前的热电材料应用失败的原因是没有有效的温度差，选C
【小题3】标题确定题：从整篇文章和第二段的句子：Gang Chen of the Massachusetts Institute of Technology and Zhifeng Ren of Boston College therefore propose an alternative.可知这篇文章讲的是太阳光发电的一个新的方法。选B
考点：考查科普类短文