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时间:2018-12-21
《课堂新坐标2016_2017学年高中英语unit4exploringplanetsperiodⅳusinglanguage学业分层测评新人教版》由会员上传分享,免费在线阅读,更多相关内容在教育资源-天天文库。
1、Unit4ExploringplanetsPeriodⅣUsingLanguageⅠ.单词拼写1.Whydidhumans(进化)towalkupright?2.I(附加)acopyofmynotesforyourinformation.3.SinceI'mhere,I'dliketotrya(有代表性的)dishofthiscountry.4.Thedyingfirewasthrowingouta(暗的)redlight.5.Don'tgraspatthe(脆弱的)branch,oryouma
2、ybreakit.6.Thewindowframeshave(腐烂)awaycompletely.7.Therearesome(甲虫)ontheplants.8.Theflowerhasseven(花瓣).9.Theairwas(芬芳的,芳香的)withscentsfromtheseaandthehills.10.Themeatgivesoutanunpleasant(气味).【答案】 1.evolve 2.attach 3.typical 4.dull 5.delicate 6.rotted
3、7.beetles 8.petals9.fragrant 10.odourⅡ.阅读理解AHaveyoueverwonderedwhystems(茎)growupwardsandrootsdownwards?Whyplantsalwaysseemtoturntowardsthelightandclimbingplantsrunupratherthandown?Theanswerissimple:auxin(生长素),achemicalsubstancethatcontrolsgrowthinpla
4、nts.AuxingivesawayitssecretsAuxinisaplanthormone(激素).Darwinwasalreadyinterestedinitinthe19thcentury.Onlyinrecentyears,however,hasthehormonestartedtogiveawayitssecrets,thankstointensivemolecularresearch.Auxinisproducedintheyoung,growingpartsofplantsan
5、dthentransportedthroughouttheplant—toalowlyingstemforexample.Thestemneedstostraightenoutassoonaspossibletobeabletoabsorbthetopside,resultingintheundersidegrowingfasterandthestemstraighteningout.Forthesamereason,plantsinfrontofwindowswillalwaysturntot
6、helight.Thisactiveregulationofauxintransportallowsplantstotakeidealadvantageoflocalandchangingconditions.AnewmeansoftransportforauxinThetransportofauxinthroughtheplantplaysavitalrole.And,fromallappearances,itisnotasimplematter.Theresearchersidentifie
7、danimportantnewlinkandmeansoftransportforauxin:PILSproteins(蛋白质).PILSproteinsarevitalforauxindependentplantgrowthandadjusttheintracellular(细胞内的)storageofthehormone.Itisexactlythiscompartmentalizing(分类)ofauxinthatseemsfunctionallyimportantforthevariou
8、sdevelopmentalprocesses.Growingcropsmoreefficiently:therightamountofauxinintherightplaceHigherauxinlevelsattherightmomentandintherightplaceresultinbettergrowthandgreaterharvest.Betteradjustmentofauxinlevelswouldmakeplantsgrowmoreefficiently.Theresear
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