职称英语理工a阅读理解必考文章字典版_1

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1、第九篇AnEssentialScientificProcess一个至关重要的科学过程Alllifeontheearthdependsupongreenplants.Usingsunlight,theplantsproducetheirownfood.Thenanimalsfeedupontheplants.Theytakeinthenutrientstheplantshavemadeandstored.Butthat’snotall.Sunlightalsohelpsaplantproduceoxygen.Someoftheoxygenisusedbytheplant,b

2、utaplantusuallyproducesmoreoxygenthanituses.Theexcessoxygenisnecessaryforanimalsandotherorganismstolive.Theprocessofchanginglightintofoodandoxygeniscalledphotosynthesis.Besideslightenergyfromthesun,plantsalsousewaterandcarbondioxide.Thewatergetstotheplantthroughitsroots.Thecarbondioxideen

3、terstheleavesthroughtinyopeningscalledstomata.Thecarbondioxidetravelstochloroplasts,specialcellsinthebodiesofgreenplants.Thisiswherephotosynthesistakesplace.Chloroplastscontainthechlorophyllsthatgiveplantstheirgreencolor.Thechlorophyllsarethemoleculesthattraplightenergy.Thetrappedlightene

4、rgychangeswaterandcarbondioxidetoproduceoxygenandasimplesugarcalledglucose.Carbondioxideandoxygenmoveintoandoutofthestomata.Watervaporalsomovesoutofthestomata.Morethan90percentofwateraplanttakesinthroughitsrootsescapesthroughthestomata.Duringthedaytime,thestomataofmostplantsareopen.Thisal

5、lowscarbondioxidetoentertheleavesforphotosynthesis.Asnightfalls,carbondioxideisnotneeded.Thestomataofmostplantsclose.Waterlossstops.Ifphotosynthesisceased,therewouldbelittlefoodorotherorganicmatterontheearth.Mostorganismswoulddisappear.Theearth’satmospherewouldnolongercontainoxygen.Photos

6、ynthesisisessentialforlifeonourplanet.练习：1．Inthefirstparagraph，theword“excess”means.B　extra.2．Whichofthefollowingdoesnotmovethroughaplant’sstomata?D　Food.3．Inthetitle,thetermEssentialScientificProcessreferstoA　photosynthesis.4．ThispassageisprimarilydevelopedbyA　explainingaprocess.5．Anothe

7、rgoodtitleforthispassagewouldbeC　HowPhotosynthesisWorks.第二十二篇RealWorldRobots现实世界中的机器人Whenyouthinkofarobot,doyouenvisionashiny,metallicdevicehavingthesamegeneralshapeasahumanbeing,performinghumanlikefunctions,andrespondingtoyourquestionsinamonotonevoiceaccentuatedbyh