首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Scientists are searching for ways to destroy nuclear weapons in space—to make nuclear weapons powerless and no longer useful. Th
Scientists are searching for ways to destroy nuclear weapons in space—to make nuclear weapons powerless and no longer useful. Th
admin
2013-03-27
42
问题
Scientists are searching for ways to destroy nuclear weapons in space—to make nuclear weapons powerless and no longer useful. This has become known as "Star Wars".(1)
Supporters of the Star Wars defense system hope that this would not only protect a nation against an actual nuclear attack, but would be enough of a threat to keep a nuclear war from ever happening.
(2)
Opponents of Star Wars are worried that a system might introduce nuclear weapons into outer space and might not completely protect the nation against attack.
Some missiles might "leak through" the Star Wars defenses. Or the computers that run the system might not work properly. Such a defense system, they say, might also be used to attack others. And it might not stop the buildup of ground-based nuclear weapons.
Hopefully, a nuclear war will never begin. But, in such an event, could people really protect themselves? Supporters of Star Wars believe that laser weapons are the key to defense.(3)
But can laser beams be developed in such a way to destroy attacking missiles in space?
Lasers are not new. They have been around for over 25 years. They involve the following process;(4)
Atoms of certain substances are stimulated, or excited, by a burst of energy from outside. The excited atoms then produce waves of light.
These light waves travel up and down a laser rod and excite, or stimulate, other atoms. When a particular energy level is reached, the laser rod produces a strong, narrow beam of radiation. Most lasers give off visible light, but they can be built to produce heat radiation or even X-ray radiation.
Because of the intensity and narrowness of their beams, lasers can be put to thousands of uses. Laser beams have been bounced off the moon. They can cut through diamond or steel. They are used by doctors for delicate surgery—such as repairing damaged eyes. And lasers are also used as weapons.(5)
They can give artillery an accuracy as sharp as the point of a pin. They can also "blind" electronic systems in planes, tanks and ships.
This means that those electronic systems can no longer effectively find and destroy their targets.
(4)
选项
答案
某些物质的原子受到外界突然爆发的能量的刺激或激发,于是,这些受激原子产生光波。
解析
转载请注明原文地址:https://kaotiyun.com/show/6AmO777K
0
考博英语
相关试题推荐
Sociologistsusethetermpowertorefertothecapacityofpeopleorgroupstocontrolorinfluencetheactionsofothers,whet
Perhapsallcriminalsshouldberequiredtocarrycardswhichread;Fragile;HandlewithCare.Itwillneverso,thesedaystog
TheCommercialRevolutionwasnotconfined,ofcourse,tothegrowthoftradeandbanking.Includedinitalsowerefundamental
Coughsyrupsandcoldremediesthataremanufacturedwithalcoholwilllastmuchlongerthanthosepreparedwithwater.
ThementalhealthmovementintheUnitedStatesbeganwithaperiodofconsiderableenlightenment.DorotheaDixwasshockedto
Parkscontributetothequalityoftheurbanenvironment.Fortunatelyitisnolongernecessarythateverylectureoreverybook
Thecurrentpoliticaldebateoverfamilyvalues,personalresponsibility,andwelfaretakesforgrantedtheentrenchedAmerican
WheneverIhearaweatherreportdeclaringit’sthehottestJune10onrecordorwhatever,Ican’ttakeittooseriously,becaus
It’sallannualback-to-schoolroutine.Onemorningyouwavegoodbye,andthat【56】eveningyou’reburningthelate-nightoilins
Afewminutesago,walkingbackfromlunch,IstartedtocrossthestreetwhenIheardthesoundofacoindropping.Itwasn’tm
随机试题
HowlongwasDilyslate?
柱面装饰板工程量应按设计图示饰面外围尺寸以面积计算,且()。
下列税种中,属于行为税的是()。
根据《工程建设项目施工招标投标办法》规定,施工投标保证金的数额一般不得超过投标总价的(),最高不超过80万元人民币。
人防工程柴油发电机的储存间、蓄电池室等房间应采用()灯具。
关于会计政策变更和会计估计变更,下列说法中正确的有()。
某企业为增值税一般纳税人,适用的增值税税率为17%。2017年12月11日,该企业购入需要安装的生产设备一台,价款20000元,增值税3400元,安装中领用生产用材料实际成本为2000元,领用自产库存商品,实际成本为4200元,售价为5000元。2017年
软件测试通常可分为单元测试、集成测试、确认测试和系统测试,其中确认测试主要用于发现(44)阶段的错误。在集成测试时,通常可采用自顶向下增殖式集成和自底向上增殖式集成。在自底向上增殖式集成时,对每个被集成的模块(45)。对那些为众多用户开发的软件(如操作系统
"Cool"isawordwithmanymeanings.Itstraditionalmeaningisusedto【C1】______atemperaturethatisfairlycool.Astheworld
Futurepredictionenjoysthepopularitythesedays,astraditionallyfoundinChineseAstrology,andnowinonlinepsychicreadi
最新回复
(
0
)