职称英语考试基础知识通关训练

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1、大家论坛club.topsage.com2010年职称英语考试基础知识通关训练（23）训练内容：概括大意与完成句子   训练要求：阅读下面这篇短文，短文后有2项测试任务：(1)第23～26题要求从所给的6个选项中为第3～6段每段选择1个正确的小标题；(2)第27～30题要求从所给的6个选项中选择4个正确选项，分别完成每个句子。请将答案涂在答题卡相应的位置上。   ElectromagneticEnergy   1Whitelightseemstobeacombinationofallcolors.The

2、energythatcomesfromasourceoflightisnotlimitedtothekindofenergyyoucansee.Heatisgivenoffbyaflameoranelectriclight.Onacloudydayitispossibletogetasunburneventhoughyoufeelcool.Visiblelightandthekindsofenergythatproducewarmthandsunburnareexamplesofelectromagne

3、ticenergy.   2Thesunis93millionmilesfromtheearth.Yetwecanuseenergyfromthesunbecauseelectromagneticenergytravelsthroughspace.   3Manyotherkindsofenergyarealsotypesofelectromagneticenergy.Radio,television,andradarsignalstravelfromtransmitterstoreceiversasl

4、owenergyelectromagneticwaves.Infrared(红外线的)radiationisanelectromagneticwave.Whenitisabsorbedbymatter,heatisproduced.Wavesofinfraredandvisiblelighthavemoreenergythanwavesofradio,television,orradar.Ultravioletrays(紫外线)andXraysareelectromagneticwaveswitheve

5、ngreateramountsofenergy.Infraredradiationisusedincookingfoodandheatingbuildings.Sunlightandelectriclightsarepartofourrequirementsfornormalliving.Ultravioletradiationisusefulinkillingcertaindiseaseorganisms.Xraysandgammarayshavesomuchenergythattheytravelr

6、ightthroughsolidobjects.Theycanbeusedtodetectandtreatcancer.Xraysareusedinindustrytofindhiddencracksinmetal,andinmedicinetorevealbrokenbones.   4Usuallyweuseelectricitytogenerateelectromagneticenergy.Thesourceofmostofourenergyisthesun.Heatfromthesuncause

7、swatertoevaporate.Whenthewaterfallstotheearthasrain,someofitis大家论坛club.topsage.comtrappedbehinddamsandthenusedtooperateelectricgenerators.Othergeneratorsarepoweredbycoal,buttheenergystoredincoalcamefromthesun,too.   5Untilrecently,thesourceofthetremendou

8、samountofenergygivenoffbythesunwasapuzzle.Ifthesundependedonchemicalreactions,itwouldhaveusedupallitsenergylongago.Experimentswithelectromagneticradiationledtothetheorythatmasscanbeconvertedintoenergy.Aboutfortyyearsaftert