阅读下面的短文。每篇短文的后面有五个问题，每个问题有四个备选答案。请根据短文的内容选择最佳答案。每个试题计3分,共计15分。
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 objects 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.
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.
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 Potters invisibility cloak doesnt have any real competition yet.
cloak斗篷，披风 infraredadj.红外线的
reconstructv.重建 gamma ray 伽马射线
electromagneticadj.电磁的coastern.托盘，垫子
A、can now make an invisible cloak of the same kind as he uses.
C、try to invent a device Similar in idea to the invisible cloak he uses.
2.What is true of microwaves?
B、Their wavelengths are longer than those of visible light.
D、They are visible to the human eye.
A、It is made of a special material with unusual ability.
C、Microwaves pass through it when they strike it.
4.What does the word coaster mean in the passage?
B、A vessel engaged in coastal trade.
D、A resident of a coastal area.
A、scientists have not found out how his cloak works.
C、the cloaking device works only for microwaves.
答案与题解：
1.C文章的第一段告诉我们，科学家还没有发明哈里波特使用的那种隐身衣，所以不能选 A;该段还告诉我们，科学家已制造了，一种装置，这种装置能使自身或置于其中的物体不被微波发现，所以C是正确选择，也就是说，科学家发明的隐形装置和哈里波特的隐身衣仅仅在概念上相同，这同时说明B和D是错误的选择。
3.B第四段第三句说，当微波到达装置表面时，very few bounce off。very few是几乎没有的意思，所以选择B。其他选择所述内容都可以很容易在该段中找到。
5.CA句在短文中没有提到;按文章的内容B不是正确的说法;文章最后一段说，And thedevice works only for microwaves，not forvisible light，所以C是正确选择。