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
Laser A laser is used to produce very powerful beams of light./Today laser is getting wider use in more fields./ Why is las
Laser A laser is used to produce very powerful beams of light./Today laser is getting wider use in more fields./ Why is las
admin
2010-04-24
68
问题
选项
答案
Laser A laser is used to produce very powerful beams of light./Today laser is getting wider use in more fields./ Why is laser so much more powerful than other kinds of light? / Laser is a kind of light and also a form of energy./A laser beam is made up of very short waves . /These waves all have the same wavelength. /The laser beam keeps going on and off all the time./As these changes are very fast, we can but see them./During the time the laser beam is off,/the energy for the next burst of light is being built up,/so when the beam is on again, it will be a strong burst./And the laser beam doesn’t spread,/it doesn’t get wider and wider as other fight beams do./This is why the laser beam can keep all of its energy/and is so much more powerful than other light beams.
解析
转载请注明原文地址:https://kaotiyun.com/show/do2K777K
0
专业英语四级
相关试题推荐
Peoplethinkingabouttheoriginoflanguageforthefirsttimeusuallyarriveattheconclusionthatitdevelopedgradually
1 Thetrainclatteredoverpointsandpassedthroughastation.2 Thenitbegansuddenlytoslowdown,presumablyinobedience
Betweengettingupandhermeeting,thewomanhadabout______.
Ourape-menforefathershadnoobviousnaturalweaponsinthestruggleforsurvivalintheopen.Theyhadneitherthepowerfu
TheMainLibraryhasfivefloorsopentothepublic. FOURTHFLOOR:SocialSciences&History.300-399,650-
GETTINGAGRANT Whocangetthismoney?Anyonewhogetsaplaceonafirstdegreecourse,althoughastudentwhohas
Inaverybreadsense,legislationplaysthesameroleinFranceasjudicialdecisionsplayincommonlawcountries.Legislative
Oneofthemostcriticalproblems【C1】______blackandotherminorityAmericanstodayisthedifficultyofentering【C2】______soc
Itwasn’tallhardworkattheG8summitoftheworld’smostpowerfulleaders.Therewasgoodfood,lotsofglad-handing.Ifthe
Atfirstthecompanyrefusedtopurchasetheequipment,butthisdecisionwas_________revised.
随机试题
均具有燥湿化痰、祛风止痉功效的药物是
下列叙述不符合散剂制备方法一般制备原则的是
关于唾液腺肿瘤的说法正确的是
A.7%~8%B.20%~40%C.40%~50%D.60%E.50%~70%正常成年男性的血细胞比容约为
药性理论是指
生态策略,是生物在进化过程中形成的对付环境的策略。这里的环境不仅是物理环境,而且还包括同种和异种的其他生物。因此,生态策略也就是生物在广义的生态环境中形成的进化策略。根据上述定义,下列不属于生态策略的一项是:
下列说法正确的是()。
将考生文件夹下LOBA文件夹中的TUXING文件夹删除。
Lydiacanrecognize______.
Whetherworkshouldbeplacedamongthecausesofhappinessoramongthecausesofunhappinessmayperhapsberegardedasadoub
最新回复
(
0
)