题目

下列各项叙述，与北京人情况不相符的是 A．直立行走 B．人工取火 C．使用打制石器 D．过群居生活 答案：B【解析】 【分析】 【详解】 结合所学知识可知，北京人会使用天然火，会保存天然的火种，不会人工取火，选项 B符合题意；生活于距今约 70--20 万年的北京人，会直立行走，使用打制石器，已经会使用天然火，过群居生活。排除 ACD 。故选 B 。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 NobelThe 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 greenLEDs 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 worldThe 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 displaysWithout 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 NobelThe 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 green2._______ 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 world4._______ 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 displaysMany smart phones, laptops and televisions use LEDs to back-light their LCD6._______.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.