宁波理工学院外语平台第四学期阅读答案.docx

宁波理工学院外语平台第四学期阅读答案.docx

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宁波理工学院外语平台第四学期阅读答案

wastheonefieldofawarenessaboutwhichhumanshadanythingmorethanthevaguestofinsights.ItisimpossibletoknowtodayjustwhatourStoneAgeancestorsknewaboutplants,butfromwhatwecanobserveofpreindustrialsocietiesthatstillexist,adetailedlearningofplantsandtheirpropertiesmustbeextremelyancient.Thisislogical.Plantsarethebasisofthefoodpyramidforalllivingthings,evenforotherplants.Theyhavealwaysbeenenormouslyimportanttothewelfareofpeople,notonlyforfood,butalsoforclothing,weapons,tools,dyes,medicines,shelter,andagreatmanyotherpurposes.TribeslivingtodayinthejunglesoftheAmazonrecognizeliterallyhundredsofplantsandknowmanypropertiesofeach.Tothembotany,assuch,hasnonameandisprobablynotevenrecognizedasaspecialbranchof"knowledge"atall.Unfortunately,themoreindustrializedwebecomethefartherawaywemovefromdirectcontactwithplants,andthelessdistinctourknowledgeofbotanygrows.Yeteveryonecomesunconsciouslyonanamazingamountofbotanicalknowledge,andfewpeoplewillfailtorecognizearose,anapple,oranorchid.WhenourNeolithic（新石器时代）ancestors,livinginthemiddleEastabout10,000yearsago,discoveredthatcertaingrassescouldbeharvestedandtheirseedsplantedforricheryieldsthenextseason,thefirstgreatstepinanewassociationofplantsandhumanswastaken.Grainswerediscoveredandfromthemflowedthemarvelofagriculture:

cultivatedcrops.Fromthenon,humanswouldincreasinglytaketheirlivingfromthecontrolledproductionofafewplants,ratherthangettingalittlehereandalittletherefrommanyvarietiesthatgrewwild---andtheaccumulatedknowledgeoftensofthousandsofyearsofexperienceandintimacywithplantsinthewildwouldbegintofadeaway.--------------------------------------------------------------------------------1.Whichofthefollowingassumptionsaboutearlyhumansisexpressedinthepassage?

A.Theyprobablyhadadetailedlearningofplants.B.Theyenjoyedthestudyofwelfare.C.Theyattachedmuchimportancetotheirproperty.D.Theythoughtthatcultivatingcropswerenotimportant.正确答案:

Theyprobablyhadadetailedlearningofplants.题目详解:

根据问题中‘assumptionsaboutearlyhumansisexpressed’的提示，从第1段的第3句中‘adetailedlearningofplantsandtheirpropertiesmustbeextremelyancient’提供的信息判断，选项中的"Theyprobablyhadadetailedlearningofplants"符合题意。

2.Accordingtothepassage,whyhasgeneralknowledgeofbotanybeguntofade?

A.Botanyisnotconsideredasaspecialbranchofscience.B.Directcontactwithavarietyofplantshasdecreased.C.Peoplefinditdifficulttoknowthenamesofnewplants.D.Plantsarenotlongervaluedasausefulresource.正确答案:

Directcontactwithavarietyofplantshasdecreased.题目详解:

依据问题中"generalknowledgeofbotanybeguntofade"的提示，从最后一段文章的最后一句中"ratherthangettingalittlehereandalittletherefrommanyvarietiesthatgrewwild"中提供的信息判断，选项中的"Directcontactwithavarietyofplantshasdecreased"符合题意。

3.Whatdoesthesentence"Thisislogical"InPara1,line6mean?

A.Itishardtodeterminetheextentofourancestor'sknowledgeofplants.B.Itisreasonabletoassumethatourancestorsbehavedverymuchlikepeopleinpre-industrial.C.Humanlearningofplantsisverydetailedandwellorganized.D.Itisnotastonishingthatearlyhumanshadadetailedknowledgeofplants.正确答案:

Itisnotastonishingthatearlyhumanshadadetailedknowledgeofplants.题目详解:

依据问题中"Thisislogical"InPara1,line6"的提示，从第1段第4句中的"adetailedlearningofplantsandtheirproperties"中提供的信息判断，选项中的"Itisnotastonishingthatearlyhumanshadadetailedknowledgeofplants"符合题意。

4.InPara2,line4,whatistheauthor'spurposeinmentioning"arose,anapple,oranorchid"?

A.Toofferexamplesofplantsthataremoreattractive.B.Togivebotanicalexamplesthatallreaderswillrecognize.C.Tomakethepassagemorevividandpoetic.D.Toshowthediversityofbotanicallife.正确答案:

Togivebotanicalexamplesthatallreaderswillrecognize.题目详解:

根据问题中的"arose,anapple,oranorchid"的提示，从第2段第2句中"Yeteveryonecomesunconsciouslyonanamazingamountofbotanicalknowledge,andfewpeoplewillfailtorecognize"提供的信息判断，选项中的"Togivebotanicalexamplesthatallreaderswillrecognize"符合题意。

5.Therelationshipbetweenbotanyandagricultureissimilartotherelationshipbetweenzoology（thestudyofanimals）and______.A.horsebackridingB.birdwatchingC.deerhuntingD.sheepraising正确答案:

sheepraising题目详解:

根据问题中‘Therelationshipbetweenbotanyandagricultureissimilarto’的提示。

从最后一段文章倒数第2句中"Grainswerediscoveredandfromthemflowedthemarvelofagriculture:

cultivatedcrops"提供的信息判断，选项中的"sheepraising"符合题意。

Nuclearpowerplantsprovideabout17percentoftheworld'selectricity.Somecountriesdependmoreonnuclearpowerforelectricitythanothers.InFrance,forinstance,about75percentoftheelectricityisgeneratedfromnuclearpower,accordingtotheInternationalAtomicEnergyAgency.IntheUnitedStates,nuclearpowersuppliesabout15percentoftheelectricityoverall,butsomestatesgetmorepowerfromnuclearplantsthanothers.Therearemorethan400nuclearpowerplantsaroundtheworld,withmorethan100intheUnitedStates.Haveyoueverwonderedhowanuclearpowerplantworksorhowsafenuclearpoweris?

Inthisarticle,wewillexaminehowanuclearreactorandapowerplantwork.UraniumUraniumisafairlycommonelementonEarth,whichwastakenintotheplanetduringtheplanet'sformation.Uraniumisoriginallyformedinstars.Oldstarsexploded,andthedustfromtheseshatteredstarsaggregatedtogethertoformourplanet.Uranium-238（U-238）hasanextremelylonglife（4.5billionyears）,andthereforeisstillpresentinfairlylargequantities.U-238makesup99percentoftheuraniumontheplanet.U-235makesupabout0.7percentoftheremaininguraniumfoundnaturally,whileU-234isevenrarerandisformedbythedecayofU-238.NuclearFission（裂变）Anuclearfissionhappenswhenauranium-235nucleuswithaneutroncapturesanotherneutron.Thenucleusthensplitsintotwolighteratomsandthrowsofftwoorthreenewneutrons（thenumberofejectedneutronsdependsonhowtheU-235atomhappenstosplit）.Thetwonewatomsthenproducegammaradiationastheysettleintotheirnewstates.Therearethreethingsaboutthisinducedfissionprocessthatmakeitespeciallyinteresting:

?

TheprobabilityofaU-235atomcapturinganeutronasitpassesbyisfairlyhigh.Inareactorworkingproperly（knownasthecriticalstate）,oneneutronejectedfromeachfissioncausesanotherfissiontooccur.?

Theprocessofcapturingtheneutronandsplittinghappensveryquickly,ontheorderofpicoseconds（1xlO-2seconds）.?

Anincredibleamountofenergyisreleased,intheformofheatandgammaradiation,whenasingleatomsplits.Thetwoatomsthatresultfromthefissionlaterreleasebetaradiationandgammaradiationoftheirownaswell.Theenergyreleasedbyasinglefissioncomesfromthefactthatthefissionproductsandtheneutrons,together,weighlessthantheoriginalU-235atom.ThedifferenceinweightisconverteddirectlytoenergyatarategovernedbytheequationE=mc.InorderforthesepropertiesofU-235towork,asampleofuraniummustbeenrichedsothatitcontains2percentto3percentormoreofuranium-235.Three-percentenrichmentissufficientforuseinaciviliannuclearreactorusedforpowergeneration.Weapons-gradeuraniumiscomposedof90-percentormoreU-235.InsideaNuclearPowerPlantTobuildanuclearreactor,whatyouneedissomemildlyenricheduranium.Typically,theuraniumisformedintopellets（芯块）withapproximatelythesamediameterasacoinandalengthofaninchorso.Thepelletsarearrangedintolongrods,andtherodsarecollectedtogetherintobundles.Thebundlesarethentypicallysubmergedinwaterinsideapressurevessel.Thewaterisusedtolowertheheat.Inorderforthereactortowork,thebundle,submergedinwater,mustbeslightlysupercritical.Thatmeansthat,lefttoitsowndevices,theuraniumwouldeventuallyoverheatandmelt.Topreventthis,controlrods（棒）madeofamaterialthatabsorbsneutronsareinsertedintothebundle.Raisingandloweringthecontrolrodsallowoperatorstocontroltherateofthenuclearreaction.Whenanoperatorwantstheuraniumcoretoproducemoreheat,therodsareraisedoutoftheuraniumbundle.Tocreatelessheat,therodsareloweredintotheuraniumbundle.Therodscanalsobeloweredcompletelyintotheuraniumbundletoshutthereactordowninthecaseofanaccidentortochangethefuel.Theuraniumbundleactsasanextremelyhigh-energysourceofheat.Itheatsthewaterandturnsittosteam.Thesteamdrivesasteamturbine,whichspinsageneratortoproducepower.Insomereactors,thesteamfromthereactorgoesthroughasecondary,intermediateheatexchangertoconvertanotherloopofwatertosteam,whichdrivestheturbine.OutsideaNuclearPowerPlantOnceyougetpastthereactoritself,thereisverylittledifferencebetweenanuclearpowerplantandacoal-firedoroil-firedpowerplantexceptforthesourceoftheheatusedtocreatesteam.Thereactor'spressurevesselistypicallyhousedinsideaconcretelinerthatactsasaradiationshield.Thatlinerishousedwithinamuchlargersteelcontainmentvessel.Thisvesselcontainsthereactorcoreaswellthehardwarethatallowsworkersattheplanttorefuelandmaintainthereactor.Thesteelcontainmentvesselisintendedtopreventleakageofanyradioactivegasesorfluidsfromtheplant.Finally,thecontainmentvesselisprotectedbyanoutercon