ResearchersfromtheUniversityof-查字典问答网

来自顾慧平的问题

　　ResearchersfromtheUniversityofHaifa-Oranimhavemanagedtomakeoutthe"self-irri-gating"mechanism(构造)ofthedesertrhubarbwhichenablesittoharvest16timestheamountofwaterthanotherwiseexpectedforaplantintheNegevDeser

　　 ThedesertrhubarbgrowsinthemountainsofIsrael'sNegevDesertwheretheaveragerainfallisparticularlylow(75mmperyear).Unlikemostoftheotherdesertplantspecieswhichhavesmallleavessoastoreducewaterlossthisplantisuniqueinthatitsleavesarepar?ticularlylarge.

　　 ProfessorSimchaLev-YadunProfessorGidiNe'emanandProfessorGadiKatzircameacrossthisuniqueplantwhilestudyingthefieldareaandnoticedthatitswaxyleavesareunusuallylarge.Theyobservedaridged(成脊状的)structureoneachleaf.

　　 Thescientistsexplainedthatthesedeepandwidedepressions(凹陷)intheleavescreatea"channeling"mountainlikesystembywhichtherainwaterischanneledtowardthegroundsur?roundingtheplant'sdeeproot.Otherdesertplantssimplyabsorbtherainwaterthatgoesthroughthegroundinitsimmediatesurroundings.

　　 Thefindingshaveshownthatthenaturalselectionprocesshasresultedintheevolutionofthisplant'sextremelylargeleaveswhichimproveditsabilitytosurviveinthearidclimateofthedesert.Theresultsofexperimentsandanalysisoftheplant'sgrowth―inanareawithanaverageannualrainfallof75 mm―showedthatthedesertrhubarbisabletoharvestquantitiesofwaterthatare16 timestheamountofwaterharvestedbythesmallleafedplantsoftheNegevDesert.WhentheresearchteamwateredthepJantartificiallytheyobservedhowthewaterflowsalongthecourseoftheleaves'depressionstothegroundsurroundingtheplant'ssinglerootandthengoesthroughthegroundtoadepthof10cmormore.Undertheexperimentalcondi?tionswatergoesthroughthegroundonlyasdeepas1cm."Weknowofnootherplantinthedesertsoftheworldthatfunctionsinthismanner"theresearchersconcluded.

　　( )1.Whatisthebesttitleforthispassage?

　　 A.HowPlants'"Selfirrigating"MechanismWorks

　　 B.HowPlantsGrowingintheDesertSurvive

　　 C.ADesertPlantGrowingintheNegevDeser

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2020-12-19 00:00

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董丽敏

　　1-4DCBA

　　A篇：以色列内盖夫沙漠中生存着一种奇特的植物——沙漠大黄能够用自己的叶子给自己浇水。

　　1.D主旨大意题。本文介绍了一个植物新发现——沙漠大黄，它能够用自己的叶子给自己浇水，故答案为D.

　　2.C细节理解题。根据第一段"...whichenablesittoharvest16timestheamountofwaterthanotherwiseexpectedforaplantintheNegevDesert."可知答案为C。

　　3.B推理判断题。根据第二段"...Unlikemostoftheotherdesertplantspecieswhichhavesmallleavessoastoreducewaterloss…"可推断答案为B.

　　4.A推理判断题。根据末段"Weknowofnootherplantinthedesertsoftheworldthatfunc?tionsinthismanner"可推断，答案为A.

2020-12-19 00:01:22

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