Invisibility Ring

　　Scientists can’t yet make an invisibility cloak1 like the one that Harry Potter2 uses.But，for the first time，they’ve constructed a simple cloaking device that makes itself and somethingplaced inside it invisible to microwaves.

　　When a person “sees” an object，his or her eye senses many different waves of visiblelight as they bounce off the object.The eye and brain then work together to organize thesesensations and reconstruct the object’s original shape. So，to make an object invisible，scientists have to keep waves from bouncing off it.And they have to make sure the objectcasts no shadow.Otherwise，the absence of reflected light on one side would give the obiectaway.

　　Invisibility isn’t 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.

　　The scientists’ new “invisibility device” is the size of a drink coaster and shaped like aring.The ring is made of a special material with unusual ability.When microwaves strike thering，very few bounce off it.Instead，they pass through the ring，which bends the waves allthe way around until they reach the opposite side.The waves then return to their originalpaths.

　　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.

　　When the researchers put a small cdpper loop inside the ring，it，too，is nearly invisible. However，the cloaking device and anything inside it do cast a pale shadow.And the deviceworks only for microwaves，not for visible light or any kind of electromagnetic radiation.So，Harry Potter’s invisibility cloak doesn’t have any real competition yet.

　　詞匯：

　　invisibility/invizE5biliti/n.看不見，無形 spectrum/5spektrEm/n.光譜

　　cloak/klEuk/斗篷，披風 infrared/5infrE5red/adj.紅外線的

　　microwave/5maikrEuweiv/n.微波 ultraviolet ray 紫外線

　　reconstruct/5ri:kEn5strQkt/v.重建 gamma ray 伽馬射線

　　radiant/5reidjEnt/adj.輻射的 wavelength/5weivleNW/n.波長

　　electromagnetic/IlektrEJ5mA^nItIk/adj.電磁的coaster/5kEustE(r)/n.托盤，墊子

　　練習：

　　1.Harry Potter is mentioned in the passage，because scientists

　　Acan now make an invisible cloak of the same kind as he uses.

　　Btry to 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.

　　Dknow that it is possible to make an invisible cloak of the same kind.

　　2.What is true of microwaves?

　　ATheir wavelengths are shorter than those of visible light.

　　BTheir wavelengths are longer than those of visible light.

　　CThey are different from visible light as they are a kind of radiant energy.

　　DThey are visible to the human eye.

　　3.What is NOT true of the invisibility device?

　　AIt is made of a special material with unusual ability.

　　BMicrowaves bounce off it when they strike it.

　　CMicrowaves pass through it when they strike it.

　　DIt bends the microwaves all the way around until they reach the opposite

　　side.

　　4.What does the word “coaster” mean in the passage?

　　AA disk or plate placed under a drinking glass to protect a table top.

　　BA vessel engaged in coastal trade.

　　CA roller coaster.

　　DA resident of a coastal area.

　　5.Harry Potter’s invisibility cloak doesn’t have any real competition yet，

　　because

　　Ascientists have not found out how his cloak works.

　　Bthe cloaking device is a total failure.

　　Cthe cloaking device works only for microwaves.

　　Dthe cloaking device works only for visible light.

　　答案與題解：

　　1.C文章的第一段告訴我們，科學家還沒有發(fā)明哈里·波特使用的那種隱身衣，所以不能選 A;該段還告訴我們，科學家已制造了，一種裝置，這種裝置能使自身或置于其中的物體不被微波發(fā)現(xiàn)，所以C是正確選擇，也就是說，科學家發(fā)明的隱形裝置和哈里波特的隱身衣僅僅在概念上相同，這同時說明B和D是錯誤的選擇。

　　2.B第三段最后一句中告訴我們，A是錯誤選擇，B是正確選擇。該段第三句說，微波與可見光一樣都是一種輻射能，所以C的說法是錯誤的，不能選擇;根據(jù)該段第一句：with wavesof light that the human eye can see和第三句：Like visible light，可以得知D是錯誤的說法，也不能選擇。

　　3.B第四段第三句說，當微波到達裝置表面時，very few bounce off。very few是幾乎沒有的意思，所以選擇B。其他選擇所述內(nèi)容都可以很容易在該段中找到。

　　4.A第四段第一句告訴我們，科學家的這個隱形裝置和一個杯墊差不多大小，所以A是正確選擇。coaster是一個多義詞，其他幾個選擇是該詞的其他意思，B：從事沿海貿(mào)易的船;C：過山車，摩天輪;D：海岸地區(qū)居民。

　　5.CA句在短文中沒有提到;按文章的內(nèi)容B不是正確的說法;文章最后一段說，And thedevice works only for microwaves，not forvisible light，所以C是正確選擇