【题目】任务型阅读
请认真阅读下面短文,并根据所读内容在文章后表格中的空格里填入最适当的单词。注意:每空一个单词。
Why Blue LED Lights Won the Nobel
The 2014 Nobel Prize in physics went to three scientists who gave lighting a big change by inventing blue LED lights. A big change in lighting efficiency is under way around the world.
Save and green
LEDs use less energy than other forms of lighting. A typical LED bulb(灯泡) can produce around 83 lumens per watt — a measure of how much brightness you can get from a unit of electrical power — much more efficient than other lighting facilities.
LEDs produce light by passing electric current through a semiconductor, while traditional bulbs pass current through a wire. The wasted heat energy is chiefly why traditional bulbs are so much less efficient.
LEDs also last about 30 times longer than traditional bulbs, and many LED bulb products promise up to 25,000 hours of use — more than 17 years if you used one for about four hours a day.
Lighting the world
The lighting transformation is not only in homes. LEDs are also being used for street lights, public holiday and decorative displays, commercial buildings, and other large energy users.
Car lighting is another application where LEDs are making progress. LEDs used to be used only for daytime running lights, but now many new cars have LED headlights for night-time use.
LEDs also hold promise for bringing light to the more than 1.5 billion people around the world without access to electricity, the Royal Swedish Academy of Sciences noted. Indeed, several proposed solutions to energy poverty include the distribution of LED lights, particularly solar-powered ones.
Digital displays
Without blue LEDs, the world wouldn’t have back-lit smart phones, TV and computer LCD screens, blu-ray(蓝光) players, many forms of lighting, and countless other products.
In the electronics industry, LEDs provide back lighting for LCD screens in many smart phones, laptops, and televisions. The LEDs are more energy efficient and allow for very thin displays.
Blu-ray players use blue LED lasers(激光) to read data off a digital optical disc. When these systems switched from using an infrared(红外线) laser to a blue LED laser, it became possible to store five to 10 times as much data.
LEDs are now being explored for their potential uses to transmit(传送) data from the Internet across open space, similar to WiFi. Such a system could transmit a lot more data than WiFi alone. This high bandwidth is possible because LEDs can turn on and off millions of times per second.
The rise of LED lighting came at a time when people were just starting to be concerned about global warming. Because of LEDs’ energy efficiency, using them for the world’s lighting would affect environmental protection in a positive way.
Why Blue LED Lights Won the Nobel
The reason why blue LED lights won the 2014 Nobel Prize in physics is that they are to 【1】______ in big changes in lighting. | |
Save and green | 【2】_______ with other forms of lighting, LEDs are much more efficient because of the different ways they pass electric current. What’s more, LED bulbs can be 【3】_______ 30 times longer than traditional bulbs. |
Lighting the world | 【4】_______ from household applications of LED bulbs, they can also be used as street lights and car headlights. |
Because of their high efficiency, LEDs, especially solar-powered ones, 【5】_______ to light areas without access to electricity. | |
Digital displays | Many smart phones, laptops and televisions use LEDs to back-light their LCD【6】_______. |
By using blue LED lasers, blu-ray players are likely to store 【7】________ data. | |
People are now exploring more 【8】_______ uses of LEDs such as transmitting data. | |
【9】_______ | LED lighting will have a positive 【10】________ on environmental protection. |
【题目】With online courses, anyone can acquire knowledge in any field of interest for free. All you need is a computer, laptop or Smart phone, internet connection and a self-made schedule. You can even get a certificate on completing the course.
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Academic Earth It has linked to over 750 online courses and 8,500 individual online lectures, giving students of all ages access to college courses they may otherwise never experience. Whether learning existing coursework, or learning for the sake of learning, anyone has the freedom to learn at their own pace from world-famous experts, without being charged more. Learn more at http://academicearth.com |
UC Berkeley It offers courses in bio-engineering, Japanese, legal studies and public health. Since they are recordings of actual lectures, they lack lecture notes and extra materials. However, each course has audio recordings of lectures via iTunes or video recordings of lectures via YouTube. Learn more at https://ucberkeley.com |
【1】Learners who choose Skillfeed need to ________.
A. equip themselves with the ability to use the computer
B. pay some fee if they want to continue after a month
C. have some knowledge of the design of website
D. learn to upload their own high-quality video
【2】We can learn from the passage that Academic Earth ________.
A. charges learners nothing for any course
B. has many lectures given by 8,500 lecturers
C. provides college courses mainly to young men
D. offers college courses at the learners’ convenience
【3】If you want to improve your skill of Japanese language, you can visit ________.
A. https://skillfeed.com
B. https://ucberkeley.com
C. https://udemy.com
D. https://iTunesU.com