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Invisibility Ring Scientists cant yet make an invisibility cloak1 like the one that Harry Potter2 uses.But，for the first time，theyve constructed a simple cloaking device that makes itself and somethingplaced inside it invisible to microwaves. Invisibility isnt possible yet with waves of light that the human eye can see.But it is nowpossible with microwaves.Like visible light，microwaves are a form of radiant energy.Theyare part of the electromagnetic spectrum，which also includes radio waves，infrared light，ultraviolet rays，X rays，and gamma rays.The wavelengths of microwaves are shorter thanthose of radio waves but longer than those of visible light. To a detector set up to receive microwaves on the other side of the ring，it looks as if thewaves never changed their paths as if there were no object in the way! So，the ring is effectively invisible. 练习： Acan now make an invisible cloak of the same kind as he uses. Ctry to invent a device Similar in idea to the invisible cloak he uses. 2.What is true of microwaves? BTheir wavelengths are longer than those of visible light. DThey are visible to the human eye. AIt is made of a special material with unusual ability. CMicrowaves pass through it when they strike it. side. AA disk or plate placed under a drinking glass to protect a table top. CA roller coaster. 5.Harry Potters invisibility cloak doesnt have any real competition yet， Ascientists have not found out how his cloak works. Cthe cloaking device works only for microwaves. 答案与题解： 2.B第三段最后一句中告诉我们，A是错误选择，B是正确选择。该段第三句说，微波与可见光一样都是一种辐射能，所以C的说法是错误的，不能选择;根据该段第一句：with wavesof light that the human eye can see和第三句：Like visible light，可以得知D是错误的说法，也不能选择。 4.A第四段第一句告诉我们，科学家的这个隐形装置和一个杯垫差不多大小，所以A是正确选择。coaster是一个多义词，其他几个选择是该词的其他意思，B：从事沿海贸易的船;C：过山车，摩天轮;D：海岸地区居民。 | 
