2015年职称英语理工类概括大意模拟习题及答案（5）

　　1　An accidental discovery announced recently has taken LED lighting to a new level, suggesting it could soon offer a cheaper, longer-lasting alternative to the traditional light bulb. The breakthrough adds to a growing trend that is likely to eventually make Thomas Edison's bright invention1 obsolete.LEDs are already used in traffic lights, flashlights, and architectural lighting. They are flexible and operate less expensively than traditional lighting.
　　2　Michael Bowers, a graduate student2 at Vanderbilt University, was just trying to make really small quantum dots, which are crystals generally only a few nanometers big. Quantum dots contain anywhere from 100 to 1,000 electrons3. They're easily excited bundles of energy, and the smaller they are, the more excited they get. Each dot in Bowers' particular batch was exceptionally small, containing only 33 or 34 pairs of atoms.
　　3　When you shine a light on quantum dots or apply electricity to them, they react by producing their own light, normally a bright, vibrant color. But when Bowers shined a laser on his batch of dots, something unexpected happened. He was surprised when a white glow covered the table. The quantum dots were supposed to emit blue light4, but instead they were giving off a beautiful white glow.
　　4　Then Bowers and another student got the idea to stir the dots into polyurethane and coat a blue LED light bulb with the mix. The lumpy bulb wasn't pretty, but it produced white light singular to a regular light bulb.
　　5　LEDs produce twice as much light as a regular 60 watt bulb and bum for over 50,000 hours. The Department of Energy estimates LED lighting could reduce U. S. energy consumption for lighting by 29 percent by 2025. LEDs don't emit heat, so they're also more energy efficient. And they're much harder to break.
　　6　Quantum dot mixtures could be painted on just about anything5 and electrically excited to produce a rainbow of colors, including white. The main light source of the future will almost surely not be a bulb. It might be a table, a wall, or even a fork.

　　练习
　　1.Paragraph l ________
　　2.Paragraph 3 ________
　　3.Paragraph 5 ________
　　4.Paragraph 6 ________

　　A　LED Lighting Is Not Mature
　　B　LED Lighting Will Replace Traditional Lighting
　　C　Almost Everything Could Be the Main Light Source in the Future
　　D　LED Lighting Has Many Advantages
　　E　Bowers Made an Unexpected Discovery
　　F　LED Light Bulbs Look Lumpy

　　5.Unlike traditional lighting, LEDs do not give out heat so ________.
　　6.Edison's bright invention is likely to be outdated because ________.
　　7.Something unexpected happened during Bower's experiment when ________.
　　8.Over one quarter of energy consumption for lighting could be saved by 2025 if ________.

　　A　traditional lighting is less durable and dearer
　　B　a laser excited the quantum dots
　　C　America adopted LEDs
　　D　graduate students work hard
　　E　quantum dot mixtures are magic
　　F　it is more efficient

　　答案与题解：
　　1.B　第一段第一句、第二句是关键。第一句说LED照明经济实惠，经久耐用。第二句说爱迪生的发明将被淘汰。其意思是LED将取代传统照明源，所以B是答案。
　　2.E　Bowers做实验，目的并非寻找新照明源。量子点在激光的激发下发出白光是一次意外的发现。段中用了“unexpected”和“surprised”都说明了这一点。第一段的“accidental discovery”也佐证了这是一次偶然的发现。因此，E是答案。
　　3.D　第五段列举了应用LED照朋的不少优点，如强亮度、经久耐用、低能量消耗、不易碎等。选项D的“LED lighting has many advantages”概括了本段的大意，所以D是答案。
　　4.C　由于有了量子点混合剂涂料，几乎任何物体都能用于照明。这是本段的中心思想。所以，C是答案。
　　5.F　题干涉及的内容在第五段可以找到，有关的句子是：“LEDs don’t emit heat, so they’re also more energy efficient”，很明显，F是答案。
　　6.A　选A的依据是第一段第一句、第二句。
　　7.B　与题干有关的内容在第三段第二句、第三句中可以找到。根据这两句表达的意思，B是答案。
　　8.C　题干的“29 percent of energy consumption for lighting could be saved by 2025”可在第五段第二句中找到。题干配上选项C后表达的意思与该句的意思相符，所以C是答案。