Question

阅读理解 　　Currently, lasers give manufacturers(制造者)ultra precise(精确的)standards of measurement, unprecedented(前所未有的)cutting and drilling power, light－speed quality control, and are employed in a host of other ways．Doors may hear labels reading“Danger－invisible laser radiation－Avoid eye or skin exposure to direct or scattered radiation”, but in spite of the risk, lasers are at work in plants and businesses throughout the world．They help shape ships, cars, jewelry and electronics components．They guide cutting, drilling and tunneling．They do things no other tool can do in the same time, offering the speed of light, a heat greater than at the surface of the sun and a line straighter than any that can even be reasonably compared to ordinary rulers, tapes or survey． 　　Laser light has special qualities suited to industrial applications that no ordinaty tools can match．Intense and highly directional, laser beams can be focused to needle a huge amount of power upon a pinpoint, or on an area much smaller．By focusing the laser's beam through lenses, just as you can tighten a sunbeam with a magnifying glass so that it will burn holes in paper, it is possible to make the coherent laser light concentrate its energy on an almost unbelievably tiny spot．Narrowed by optics, a laser can drill 300 separate holes in the head of a pin．You can get an idea of the concentration(集中)of energy in this tiny spot by considering what happens if you hit a piece of wood with a hammer－at most a dent, but not much more．Hit the much smaller head of a nail with the same hammer, and you will drive the nail through the wood．Energy concentrated on a small point accomplishes much more than energy spread out over a wider area． 　　That's why coherent, tightly focused beams of laser light can do so much more than ordinary, spread out, incoherent light．You can get an idea of the difference in power between ordinary light and laser light by glancing at a household light bulb for an instant．The worst that will happen is that you will retain the image of the bulb on your retina(视网膜)for a few seconds after looking away．If you stared straight at a laser beam for even a fraction of a second, you could burn a hole clear through your retina, resulting in permanent loss of eyesight． (1) Which of the following is NOT true about laser light according to the passage? [　　] A． Laser beams are widely used in manufacturing industry． B． Laser beams are applied in medical treatment and research． C． Laser beams can reach a heat greater than that on the surface of the sun． D． Laser beams are intense and highly directional． (2) Laser light can replace all of the following tools EXCEPT ________． [　　] A． hole－puncher B． ruler C． heater D． power generator(发电机) (3) Apart from all its advantages, laser light has a disadvantage which is ________． [　　] A． direct contact with laser lights can cause permanent physical damage B． the application of laser light will eventually deprive people of their eyesight C． it can only be applied in limited areas of industry D． the application of laser light in industry is hard to achieve (4) Which of the following best explains the structure of the passage? [　　] A． A definition is given, and it is followed by various examples of application． B． Basic features are introduced, and analogies(类比)are used to give the readers a better understanding． C． An old theory is presented, and then challenged in the later half of the passage． D． Overall descriptions of the main features of laser light．

Answer 1

答案：1．B;2．D;3．A;4．B;
解析：

(1)	文章主要介绍激光在制造业的运用，在医学和研究领域的运用没有在文章中提及． 　　A项“激光在制造业的应用”，C项“激光束能够产生比太阳表面还强的热”，D项“激光束密度大、方向性强”在文章中都有明确的信息依据．
(2)	分析文章第一段所给的信息，利用排除法可得出答案．standards of measurement; unprecedented(前所未有的)cutting and drilling power, light－speed quality control; They help shape ships, cars, jewelry and electronics components．They guide cutting, drilling and tunneling．以上信息包含了“测量工具ruler”；“钻眼工具hole－puncher”；“供热工具heater”，只有D项未提及．
(3)	文章第一段和最后一段都提到直接接触激光对身体的危害：Doors may hear labels reading“Danger－invisible laser radiation－Avoid eye or skin exposure to direct or scattered radiation,”If you stared straight at a laser beam for even a fraction of a second, you could burn a hole clear through your retina, resulting in permanent loss of eyesight．exposure to暴露在……；result in导致；permanent loss of eyesight永久失明．
(4)	从作者拿激光跟用锤子钉钉子和研究盯着灯泡看这一类比手段可得出答案．作者为了把激光的作用浅显易懂地介绍出来用了类比的手法． 　　①laser beams can be focused to needle a huge amount of power upon a pinpoint, or on an area much smaller．②You can get an idea of the difference in power between ordinary light and laser light by glancing at a household light bulb for an instant．上述信息用了两个类比．