【文章內容簡介】 ction system analyzes what happens when wireless signals go through and bounce off objects or materials. The approach, which the paper states, works by separating the wireless interference(干擾)caused by two factors of objectsthe material and shape. Most dangerous objects such as weapons are usually metal or liquid, which have significant interference, researchers said. When it was tested on a backpack, the accuracy rate topped 95 percent. But the accuracy dropped to about 90 percent when objects inside bags are wrapped. And the tech could save lives if used in museums, stadiums, theme parks or schools, the team said, noting its design can inspect bags or luggage without being an exposure to privacy. It uses channel state information (CSI) that is readily available in lowcost WiFi devices. This could have a great impact on protecting the public from dangerous objects, said Yingying Chen, a coauthor of the study, There39。s a growing need for that now. In large public areas, it39。s hard to set up expensive screening equipment like what39。s in airports. Manpower is always needed to check bags and we want to develop a method to try to reduce manpower.” The peerreviewed study, which recently won a best paper award at the 2018 IEEE Conference on Communications and Network Security, is now published online. Future work will continue to focus on ameliorating the accuracy of identifying objects and imaging shapes and volumes, researchers said.（1）What does paragraph 3 talk about? A.The function of the technique.B.The way the device works.C.The principle the study is based on.D.The benefit of the study findings.（2）What39。s the advantage of the device? A.It saves people in danger of natural disasters.B.It passes through bags without damaging them.C.It uses antennas to pick up networks39。 signals.D.It protects personal information from being disturbed.（3）Why did the researchers study the device according to Yingying Chen? A.To save money and labour.B.To make full use of WiFi.C.To protect passengers39。 privacy.D.To research dangerous objects.（4）Which of the following can replace the underlined word “ameliorating in the last paragraph? A.Confirming.B.Improving.C.Discovering.D.Examining.【答案】 （1）B（2）D（3）A（4）B 【解析】【分析】本是一篇說明文，介紹了研究人員發(fā)現，WiFi可用于可用于安檢。 （1）考查段落大意。根據第三段中的“The detection system analyzes what happens when wireless signals go through and bounce off objects or materials.”這個檢測系統分析信號在物體和材料上穿透和反射時會發(fā)生什么?？芍xB。 （2）考查細節(jié)理解。根據第四段中的“noting its design can inspect bags or luggage without being an exposure to privacy.”可知，不用打開和檢查人們的個人物品，避免了侵犯隱私，可知選D。 （3）考查推理判斷，根據第五段中的“In large public areas, it39。s hard to set up expensive screening equipment like what39。s in airports. Manpower is always needed to check bags and we want to develop a method to try to reduce manpower.”在大型公共場所，很難像機場那樣設置昂貴的安檢設施。檢查行李總是需要人力，我們希望開發(fā)一種互補的方法來減少人力，可推知選A。 （4）考查詞義猜測。根據最后一段中的“Future work will continue to focus on ameliorating the accuracy of identifying objects and imaging shapes and volumes”今后的工作將繼續(xù)側重于提高識別物體和成像形狀及體積的準確性，故選B。 【點評】本題考點涉及細節(jié)理解，詞義猜測，推理判斷和段落大意四個題型的考查，是一篇科研類閱讀，要求考生在捕捉細節(jié)信息的基礎上，進一步根據上下文的邏輯關系，進行分析，推理，概括和歸納，從而選出正確答案。5．犇犇閱讀理解 In areas like the Central United States that get lots of tornadoes, there39。s a mon piece of celestial （天上的）fortunetelling that green skies mean a tornado is on its way. Research has shown that it isn39。t quite as simple as that, but scientists have found that if you see a green sky, you should probably go inside. As far as most scientists can tell, the green skies around powerful thunderstorms are usually a bination of red sunsets and water droplets. Daytime skies are blue because blue shorter wavelengths of visible light tend to bounce off （反射）air molecules better than red longer wavelength light. So the blue light gets bounced all over the sky and looks like it39。s ing from everywhere. Meanwhile, around sunset sunlight travels through so much atmosphere that just about all the blue is bounced away from the horizon, leaving all those reds and oranges behind. The sunset might look exclusively （獨有的）red and orange, but there39。s still some green and even blue light hidden in there, just far less than the other colors. But for us to notice the remaining green light, it needs to hit something that reflects green light much better than red. That39。s where water es in. Big tall threatening storm clouds are made of water droplets, and even though water is best at reflecting blue light, it can still reflect green pretty well, much better than reds and oranges, so under just the right conditions, the water in and around a cloud can bounce the green light hidden in the sunset right into our eyes making the sky look green. Still, none of the conditions that can turn skies green are unique to the clouds that produce tornadoes. Sometimes they just lead to lots of rain, and maybe some hail. So if you see huge storm clouds rolling in and a green tint （色調）in the sky, it doesn39。t necessarily mean there39。s about to be a tornado, but it does mean you should probably head indoors.（1）What can be the best title for the text? A.Why Do the Central United States Get TornadoesB.Do Green Skies Mean a Coming TornadoC.A Common Piece of Celestial FortunetellingD.Green Skies Are Unique to Clouds（2）Why are the skies blue in the daytime? A.Because only blue light can be bounced in the daytime.B.Because there is more blue light than light of other colors.C.Because blue light is bounced all over the sky.D.Because red light is weaker than blue light.（3）What does the underlined word it in paragraph 2 refer to? A.The sunset.16