题目

Your best friend that follows you around when the sun comes out - your shadow - doesn’t serve an important function like your heart or brain, but what if you could use shadows to create electricity? When using solar panels ( 电池板 ) that are powered by light, shadows can be boring because it means electricity can’t be created. However, researchers from the National University of Singapore have engineered a way to create power from the shadows present everywhere. A team of the university created a machine that can collect energy from shadows. It is created by placing a thin coating of gold onto silicon ( 硅 ). Like in a normal solar panel, when put in light, the silicon electrons ( 电子 ) become energized and the energized electrons then jump from the silicon to the gold. The voltage ( 电压 ) of the part of the machine that is placed in the light increases relative to the dark part and the electrons in the machine flow from high to low voltage. They are sent through an external circuit ( 外电路 ) creating a current that can be used to power another machine. The greater the contrast between light and dark, more energy is provided by the machine. The team is working on improving the performance of the machine, borrowing approaches from solar panels to gather light. Increasing the amount of light the machines can receive allows them to better make use of shadows, as well as developing shadow energy collecting panels that can successfully gather from indoor lighting. The team is also researching the use of other materials other than gold to drop the price of the machine, meaning they would be more cost effective and easier to apply in society. Shadows are present everywhere and perhaps one day in the future we will be able to collect energy from them by placing the shadow-effect energy machine around the world in places that have been considered unfit for solar panels to work, or indoors. “A lot of people think that shadows are useless,” Tan says, but “anything can be useful, even shadows.” 1 ． What is Paragraph 1 mainly about? A ． Your best friend always stays with you after the sunrise. B ． The shadow has the same function as the heart and brain. C ． Shadows can stop solar panels from creating electricity. D ． Researchers have found a way to create power from shadows. 2 ． What is the key working principle of the machine mentioned in the text? A ． The silicon produces electricity when it is in the light. B ． The gold produces power with the help of the silicon. C ． The energized electrons flow from high to low voltage. D ． An external circuit creates current using another machine. 3 ． How does the team improve the performance of the machine? A ． Using solar panels in the machine. B ． Increasing the amount of light received. C ． Developing light energy collecting panels. D ． Bringing down the price of gold. 4 ． Which of the following is the best place to apply the machine? A ． A gym. B ． A park. C ． A farm. D ． A playground.   答案：1 ． D 2 ． C 3 ． B 4 ． A 【分析】 本文是说明文。文章介绍了研究人员设计出的从阴影中收集能量的办法。 1 ． 主旨大意题。根据第一段的 “However, researchers from the National University of Singapore have engineered a way to create power from the shadows present everywhere.( 然而，来自新加坡国立大学的研究人员已经设计出了一种从世界各地的阴影中创造力量的方法 )” 可知，第一段讲述研究人员已经找到了一种从阴影中创造力量的方法。故选 D 。 2 ． 细节理解题。根据第二段的 “Like in a normal solar panel, when put in light, the silicon electrons ( 电子 ) become energized and the energized electrons then jump from the silicon to the gold. The voltage ( 电压 ) of the part of the machine that is placed in the light increases relative to the dark part and the electrons in the machine flow from high to low voltage. They are sent through an external circuit ( 外电路 ) creating a current that can be used to power another machine. The greater the contrast between light and dark, more energy is provided by the machine.( 就像在普通的太阳能电池板中一样，当放入光中时，硅电子变成能量，有能量的电子然后从硅跳到黄金。机器放置在光中的部分的电压相对于暗部分增加，机器中的电子从高压流动到低压。它们通过外部电路发送，产生一种可用于为另一台机器供电的电流。明暗之间的对比度越大，机器提供的能量就越多 )” 可知，机器工作原理的关键是带电的电子从高压流到低压。故选 C 。 3 ． 细节理解题。根据第三段的 “The team is working on improving the performance of the machine, borrowing approaches from solar panels to gather light. Increasing the amount of light the machines can receive allows them to better make use of shadows, as well as developing shadow energy collecting panels that can successfully gather from indoor lighting.( 该团队正在努力提高机器的性能，利用太阳能电池板的方法来收集光线。增加机器可以接收到的光线的数量，使它们能够更好地利用阴影，以及开发可以从室内照明中成功收集到的阴影能量的收集面板 )” 可知，这个团队通过增加接收到的光的数量提高机器的性能。故选 B 。 4 ． 推理判断题。根据最后一段的 “Shadows are present everywhere and perhaps one day in the future we will be able to collect energy from them by placing the shadow-effect energy machine around the world in places that have been considered unfit for solar panels to work, or indoors.( 阴影无处不在，也许将来有一天，我们可以通过将阴影效应能量机器放置在世界各地被认为不适合太阳能电池板工作或在室内工作的地方，从它们那里收集能量 )” 可知，使用这种机器的最好的地方是不适合太阳能电池板工作的地方或者室内，因此推断体育馆是最好的地方，其它三个地方都是室外。故选 A 。  

查看本题答案和解析