陕科大包装技术基础双语试题（两套）及答案

陕西科技大学试题纸1课程:包装技术基础（双语授课）班级:包装级*班学号:*********姓名:***题号一二三四五六七八九十总分得分

阅卷人

一、PackagingTerms(名词解释)(15points)：（用中文解释下面术语）packaging;corrugatedboard;TetraPak;MAP;thermoplastics二、TrueorFalse(判断题)(16points)：1.Typically,theinform/sellfunctionplaysamoresignificantroleinindustrialpackaging.2.Topreventaproductfromdamageresultedfromvibration,theprotectivepackagingshouldtakeintoaccounttheresonantfrequenciesoftheproduct.3.Vacuumpackagingcanbeusedinfruitsandvegetables.4.Immediateadvantagesoftwo-piececansarereducedmetalusage,improvedappearance,andtheeliminationofapossibleleakagelocation.5.DoubleWallreferstothreesheetsoflinerboardwithtwomediumsinbetween.6.Paperpropertiesdependsuponthepaper'sdirectionality7.Iftheg-factorisestimatedtoolow,theproductwillbeunder-packaged.8.Significantcompressivecreepwillleadtothepackageditemlooseninginthecushion.三、MultipleChoices(单选题)(30points)：(The15choicesarebaseduponthefollowingmessage)LiquidConstantLevelFillingIntroduction.Althoughtheremaybeslightvariationsinthesizesorshapesofbottlesandjars,itisfrequentlydesirabletohavethefilllineatthesameheightoneachcontainersothatallofthemappeartobefilledexactlythesamewhentheyareonthedisplayshelf.Somemanufacturersdeliberatelyaddextraproductandoverfillsomeoftheir“seethrough”containersinordertoimprovetheirappearanceandtoguaranteethatallofthemcontainatleasttheminimumdesiredamountofproduct.Inthissectionyouwilllearntheoperationoffivebasicmethodsusedforconstantlevelfillingofstillliquidsandsemi-liquidsandonemethodusedforfillingcarbonatedproducts.Youwillalsolearnwaysinwhicheachmethodisusedandtheirbasicmachinemaintenancerequirements.Moldingandformingtechniquescancauseminorirregularitiesinthesizesofshapesofrigidglassandplasticbottlesandjars,andsomesemi-rigidcontainersmayalsochangetheirshapeandvolumeslightlyduringthefillingprocess.Itisfrequentlymoreeconomicaltouseadditionalproductintheoversizedcontainersthanitwouldbetomorecloselycontroltheformingprocesses1.Constantlevelfillingtechniquescompensatefortheminorchangesandvariationsinthecontainersandproducetheuniformappearancethatisimportantinthesaleofmanyproductsin“seethrough”containers.PureGravityFilling.Puregravity(Figure20.14)isnotonlyoneoftheoldestandsimplestconstantlevelfillingmethods,butitisalsooneofthemostaccurateonesforfillingfree-flowingproducts.Somegravityfillerscaneliminatetheneedforoverflowandrecirculationoftheproduct,andsomecanholdaerationoftheproducttoaminimum.Puregravityfillingcanbeusedformoststillliquidsandsomesemi-solids.Productswithconsistenciesasheavyascatsupormustardcanbefilledinthisway,butcaremustbetakenwiththeheavierproductstoassurethatthetemperatureandconsistencyoftheproductismaintainedatalevelatwhichtheproductflowsfreelyandevenly.Althoughtheconstantlevelfillerscanbeadjustedtoautomaticallyoperateatslowerspeedswhentheproductflowsmoreslowly,thischangeinrateofflowcanaffectthetimingoftheconveyingsystemandothermachinesinthepackagingline.Theproductflowisproducedinthepuregravitysystembylocatingtheproductsupplytankhighenoughsothatforcesofgravitycanbeusedtomovetheproductthroughthefeedmechanismsintothecontainers.Theflowisstartedandstoppedbytheactionofaspringloadedfillingvalvethatisopenedbytheforceofmakingcontactwiththetopofthecontainer.Somemachinesplacethecontaineronaplatformandraiseitupagainstthevalveinthefillerhead,andotherslowerthefillerheaddownontothetopofthecontainer.Whenthepressureofthecontactissufficient,thespringopensthefillingvalve,andtheproductflowsfromFigure20.14Puregravityfillingthesupplytankintothecontainer.Inthemachineshownintheaboveillustration,theairinthecontainerisforcedoutthroughtheventtubeastheproductentersthecontainer,andwhentheliquidcoverstheportoftheventtubetheaircannolongerescape.Thebackpressurestopstheflowofproductintothecontainer.Whenthecontactbetweenthefillerheadandthecontainerisbrokenthespringclosesthefillervalveandpreventsdrippingoftheproductastheheadisremovedfromthecontainerandpositionedforthenextfill.Someothertypesofgravityfillersusetimingdevicestoopenandclosethevalvestocontroltheflowofproductintothecontainers.Insteadofanairventtube,anoverflowpipeislocatedatthefilllinetocarryanyexcessproductintoanoverflowtankfromwhichitcanbepumpedbackintothesupplytank.Thistypeofsystemdoesnotrequireatightsealbetweenthecontainerandthefillerhead.Themaintenancerequirementsofthepuregravityfillingsystemarerelativelysimple.Thefillercomponentsmustbekeptcleanandwelllubricated,andthebearings,bushings,andspringsmustbereplacedwhentheywearexcessively.Themovementofthemachinepartsmustbemonitoredandadjustmentsmadetotimeandpositionthemcorrectlyforthefilllevelthatisdesired.Theconsistencyoftheproductandthefreemovementofallmovingpartsarecriticalforsmoothoperation.Underfillmaybecausedbyconstrictionoftheairventtubeorbyfailureofsufficientproducttomoveintothecontainerduringthetimeperioditisunderthefillerhead.Figure20.15PurevacuumfillingPureVacuumFilling.Purevacuumfillingsystems(Figure20.15)areusedprimarilyforfillingnarrowneckedglassbottleswithstillliquids.Itisnotnormallyusedwithplasticorothernon-rigidcontainers,becausethevacuumpressurethatisusedtodrawtheproductfromthestoragetankintothecontainercancausenon-rigidcontainerstocontractandbecomedistorted.AsshowninFigure20.15,thevacuumtubewithinthefillingsleeveisconnectedtoavacuumchamberwhichismaintainedataconstantvacuumlevelbyavacuumpump.Whenthebottleisinposition,anairtightsealisestablishedbetweenthetopofthebottleandthefillerhead.Asthevalvesareopenedavacuumisdrawnonthebottle,andthispressuredifferentialdrawstheproductfromthesupplytankintothebottle.Thefilllevelisdeterminedbythepositionofthevacuumportinthebottle,becausetheexcessproductisdrawnoutthroughtheport.Thelengthofthefilltimeisusuallycontrolledbyacamoperationorsomeothertypeoftimingmechanism.Theproductoverflowfromthecontainerisdrawnthroughthevacuumportintothevacuumchamberonwhichavacuumismaintainedbytheactionofthevacuumpump.Theexcessproductispumpedbackintothesupplytank.Thepurevacuumfillingsystemisgenerallyfasterthanapuregravitysystem,butthevacuumsystemalwayshassomeoverflowandrecirculationofproduct.Thevacuumfillerworksonlywhenthereisasealbetweenthebottleandfillervalve,sochippedorcrackedbottlescannotbefilled.Avacuumlevelofbetween25and28inchesofmercuryisnormallymaintainedtoprovidesmoothandefficientoperation,butthelevelmayvaryondifferentmachinesasaresultofthedifferencesinmanufacturers'designsandspecifications.Thevacuumfillerissomewhatmoredifficulttocleanthanasimplegravitysystembecauseofitscomplexityandsmallvacuumtubesthatcanbecomeplugged.Allthefittingsmustbekepttightforefficientoperation.Thesealingwashersmustbereplacedwhentheyshowsignsofdamageorwear,andthereplacementsshouldalwaysbeoftherecommendedtypeandmaterial.Careshouldbetakentoassurethatthepropertypeoffillingnozzleisalwaysusedfortheproductbeingfilled,becausefoaming,aeration,andsplashingcanbeincreasedbyrapidmovementoftheproduct.Figure20.16Gravityvacuumfilling

GravityVacuumFilling.Gravityvacuumfillingsystems(Figure20.16)combinethefeaturesofboththegravityandthevacuumsystems.Alightvacuumoffrom3to5inchesofmercuryismaintainedinthesystemtoassistindrawingtheairoutofthecontainersandtostabilizetheflowoftheliquid.InthefillershowninFigure20.16alightvacuumismaintainedintheareaabovetheproductinthesupplytank,andtheventtubefromthecontaineropensintothisareaofthesupplytank.Whenthesealisestablishedbetweenthefillerheadandthebottletheventisopened,andavacuumisautomaticallydrawninthecontainer.Thisvacuuminthecontainerhelpsmaketheproductflowintoitmorerapidlyandsmoothly.Asinthegravityfillingsystems,whentheproductreachesthefillleveltheventportisclosedbytherisingliquid,andtheflowstops.Thegravityvacuumsystemdoesnothavetheoverfloworrecirculationofproductthatisinherentinthepurevacuumsystem,anditproducesminimumamountsofturbulenceandaerationoftheproduct.Thistypeofsystemisparticularlywellsuitedtofillingdistilledspiritsandwinebecausethereisvirtuallynolossofproof.Sincethefillingnozzleisspringloadedandoperatedonlywhenthevacuumispresent,achippedorcrackedbottleonwhichasealisnotformedwillnotbefilled.Thevacuumgravitysystemmustbekeptcleanandclearofanyobstructionsthatcouldaffecttheflowthroughthevacuumtubes.Thesealsandconnectionsarecriticalandshouldalwaysbekepttightandreplacedwhensignsofwearappear.PurePressureFilling.Inpurepressurefilingsystems(Figure20.17),theproductispumpedfromastoragetankthroughafillingvalveandintothecontainer.Theproductstoragetankmaybelocatedexternaltothemachineorasanintegralpartofit.

Figure20.17PurepressurefillingAproductpumpdrawstheproductfromthesupplytank,andappliesthepressurenecessarytopumpitintothecontainers.Thefillingvalvecontainsanoverflowtubetodraintheexcessproductbacktothesupplytankandpreventoverfill.Thefilllevelofthecontainerisdeterminedbythelocationoftheoverflowportinthistubewithintheneckofthecontainer.Whentheproductreachestheoverflowport,thefilliscompleted,buttheflowcontinuesthroughtheoverflowtubeuntilthesealonthecontainerisbrokenandthevalvesleevecoverstheportsinthefillingnozzleandstopstheflow.Purepressurefillingisnormallyusedforstillliquids,butitcanbeappliedtoawidevarietyofproductswithdifferentconsistencies.Applyingpressuretotheproductmaytendtoincreasesplashingorfoaming,soparticularcareshouldbetakentoinsurethattheappropriatenozzlestylesandsizesareusedandthattherecommendedpumpspeedsandpressuresettingsareused.Regularcleaningandlubricationofallmovingpartsaccordingtothemanufacturers'recommendationsisrequiredtokeepthemachinesinthetopoperatingcondition.Cleaningofthenozzlesattheendofeachrunisparticularlyimportantwithheavierproductsormaterialsthatcanbuild-upinthenozzlesandtubes.LevelSensingFilling.Levelsensing(Figure20.18)makesitpossibletofillcontainerstoalevelwithoutestablishinganairtightsealbetweenthetopsofthecontainersandthefillervalves.Itisusedprimarilyforhighspeedfillingofsmallneckedplasticandglassbottles.Thefilllevelisveryaccurate,andthereisnoneedforproductrecirculation.Apressureofupto15psigisappliedtoforcetheproductfromthesupplytankthroughtheproductvalveandintothebottle.Sincethereisnosealthedisplacedairescapesoutofthetopofthebottlearoundtheproducttube.ThesensingdeviceoperatesbydirectingastreamoflowpressureairatthefillingstationandFigure20.18Levelsensingfillingdetectingchangesintheresistancetotheairflow.Thepositioningofthefillerandthestartoftheflowcanbeinitiatedwhenthesensingdevicedetectsthepresenceoftheemptybottleinthefillingstation.Whentheproducthasfilledtothedesiredlevel,thesensingunitsignalstheinterfacevalvetostoptheflow.FillingFilledThesensingairtubeislocatedinsidethefillertube,soitmustbekeptcleanandfreeofobstruction.Asmallbuild-upofproductinsidethesensingairtubecouldcausedifferencesintheunit'ssensitivityandcauseunderfills.Theproducttubeisfrequentlydesignedforaparticularproductandbottledesign,andmaycontainscreensorotherfeaturestoreduceturbulenceorfoaming.Anewfillertubemayberequiredwhenchangesaremadeineithertheproductorthecontainer.PressureGravityFilling.Carbonatedbeveragescanlosesomeoftheircarbonationduringthefillingprocessiftheyarehandledroughlyorexposedtoopenatmosphere.Pressuregravityfilling(Figure20.19)isaprocessthatwasdevelopedspecificallytohelpholdtheCO2inthecarbonatedbeveragesduringthefillingoperation.Thismethodisusedalmostexclusivelyforfillingbeveragessuchassodas,beer,sparklingwines,andchampagnesintobottlesorcans.Inthepressuregravityfillingoperationapressureofbetween15and125psigismaintainedintheheadspaceoftheproductsupplytanktohelpholdtheCO2insolution.Otherwisethefillingisbasicallyagravityfillingprocess.Figure20.19PressuregravityfillingFillingFilledWhenthecontainerissealedtothefillingvalveamechanicallatchopensachargingvalveatthetopofthevalveventtube.Thisestablishesinthecontainerthesamepressurelevelthatisbeingappliedtothesurfaceoftheproductinthesupplytank.Theproductisinatotallypressurizedenvironment.Thispressuredoesnotinterferewiththefillingprocess,butitdoespreventthelossofcarbonation.Afterthepressureinthecontainerisequalizedwiththatinthesupplytank,thespringloadedfillervalveopensandtheproductflowsintothecontainerbygravityuntiltheventportiscoveredandtheflowisstoppedasinanormalgravityfillingprocess.Thefillingvalvealsocontainsamechanicalsniftportwhichopenstheheadspaceofeachfilledcontainertotheatmosphereinordertogentlyreleasethepressurefromthefilledcontainerandpreventgushingwhenthesealisbrokenandthefillerheadisremovedfromthecontainer.

1.Thevolumeofproductineachcontainerismoreaccuratewitha.constantlevelfillingb.levelsensingfillingc.volumetricfilling2.Theforcethatmovestheproductinagravityfillerisproducedbya.locationofthesupplytankb.rotarypumpsc.vacuumpressure3.Ongravityfillerstheventtubelocationdeterminesa.theamountofoverflowb.thefilllinec.backpressure4.Purevacuumfillersarenormallyusedwitha.glassbottlesb.plasticbottlesc.metalcans5.Inapurevacuumsystema.thereisnoproductoverflowb.productoverflowreturnsdirectlytothesupplytankc.productoverflowisdrawnintothevacuumchamber6.Atightsealbetweenthecontainerandthefillerheadisrequiredona.allgravityfillingsystemsb.purevacuumfillingsystemsc.boththeabove7.Thespeedofthepurevacuumsystemisa.fasterthanthepuregravitysystemb.slowerthanthepuregravitysystemc.aboutthesameasthepuregravitysystem8.Gravityvacuumfillersareusedlargelyforfillinga.carbonatedbeveragesb.winesc.semi-liquidproducts9.Somegravityvacuumfillerswillfillachippedbottlea.trueb.false10.Thefilllevelofapurepressurefillerisdeterminedbythelocationofa.thesensingelementb.theoverflowtubec.theventtube11.Theairfromabottlefilledbyalevelsensingsystemescapesa.throughtheventtubeb.throughtheoverflowtubec.throughthetopofthebottle12.Thesensingunitonalevelsensingfillerisoperatedbya.photoelectriccellsb.lowpressureairc.mechanicaldetectors13.Themostimportantmaintenancerequirementforfillerisa.cleaningandlubricationb.adjustmentc.overhaul14.Thepressureinapressuregravityfillerisusedtoa.movetheproductb.keeptheproductinsolutionc.preventsplashingandfoaming15.Thepurposeofthesniftportonapressuregravityfilleristoa.determinethefilllevelb.permitoverflowc.releasepressurefromthecontainer

四、Questions(回答题)(15points)：(用中文或英语回答)１．包装的功能是什么？２．产品脆值的定义是什么？３．纸板的‘基础重量'指什么？４．什么是材料的动态缓冲曲线？５．什么是包装线？

五、Discussion(论述题)(24points)：（基于所学内容，自选一‘包装专题'用中文论述）参考答案和评分标准（课程测试题一）一、每题3分，共15分packaging:包装。为在流通过程中保护产品,方便储运,促进销售,按一定技术方法而采用的容器、材料及辅助物等的总体名称。corrugatedboard：瓦楞纸板。若是三层瓦楞纸板，由两层面纸粘接于中间一层瓦楞纸上而成。五层瓦楞纸板由两层面纸、一层芯纸和两层瓦楞纸组成。另外，还有七层瓦楞纸板。TetraPak：利乐包。是来自于瑞典的一种适于液体无菌包装的容器和技术。MAP：气调包装。是一种适于食品、果蔬的包装技术。它根据被包装物的特性，通过改变包装内的气体构成比例，来延长食品、果蔬的货架寿命。thermoplastics：热塑性塑料。与热固性塑料不同，是一种完全聚合物，遇热软化后，在压力下能够流动，呈现新的形状，这时若冷却，将会形成有用的形状。这种材料的废弃物回收后能重新融化和再次加工。由于其易成型、易循环使用，所以它是主要的塑料包装材料。二、每题2分，共16分1.F2.T3.F4.T5.T6.T7.F8.T三、每题2分，共30分1.c2.a3.b4.a5.c6.b7.a8.b9.b10.b11.c12.b13.a14.b15.c四．每题3分，共15分1．Contain,Protect/Preserve,Transport,Inform/Sell.包容性、保护性/保藏性、方便运输、宣传产品/促进销售。2．Fragilityisnormallyexpressedinunitsof“g's”andindicatesthemaximumdecelerationtheproductcanwithstandwithoutbeingdamaged.Themorefragileaproductis,theloweritsg-factor.通常以g's表示。表明了产品不出现破损所能承受的最大加速度值，用产品的实际加速度与重力加速度的比值表示，所以脆值没有量纲。3．‘Basisweight'referstotheweightinpoundsper1000squarefeet,sometimesabbreviatedtolb/MSF.‘基本重量'指的是每1000平方英尺纸板有多少磅重，单位往往以lb/MSF来表示。4．Adynamiccushioningcurveshowshowaparticularpackagingmaterialofagiventhicknessbehavesatdifferentimpactconditions.Curvesaregeneratedbydroppingaseriesofknownweightsontoacushionsamplefromaspecifiedheightandmeasuringtheamountofshockexperiencedbytheweightsastheyimpactthefoam.Insimpleterms,thistestingrepresentsaproductdroppingonacushionfromaheightlikelytobeencounteredduringshipment.动态缓冲曲线表明一种特定厚度的缓冲包装材料在不同的冲击条件下表现出的性能。它的产生就是将一系列已知重量的重块从一个特定的高度跌落到衬垫式样上，此时测得这些重块撞击到泡沫材料上所承受的加速度。简单的说，该测试代表了一个产品从它在流通环境中可能遇到的高度跌落到缓冲衬垫上的情况。5．Thepackaginglineconsistsofagroupofpackagingmachineswithcontrolsthatmakethemworktogetherasone.Thepackaginglinereceivestheproduct,containers,lids,adhesives,labels,wrappingmaterial,andothermaterialsthatareneededforthepackage.Themachinesusethesematerialstoform,fill,seal,anddeliveracompletepackage.由若干个通过控制装置协调的包装机组成。它接收产品和完成一件包装所需的容器、盖、黏结剂、标签等包装用材料。包装线上的机器使用这些材料进行容器成型、充填/灌装、封口和输送包装件等。五、24分要点：选题正确、论述合理（层次清晰、观点明确、写作流畅等）、具有自己的见解。

陕西科技大学试题2课程:包装技术基础（双语授课）班级:包装级*班学号:*********姓名:***题号一二三四五六七八九十总分得分

阅卷人

说明：考试中可参阅课本等个人资料，但不能互相讨论。一、Vocabulary(词汇互译)(20points)：1.primarypackage2.environmentallyfriendlypackaging3.PMMI4.coefficientofrestitution5.dynamiccushioningcurve6.显窃启盖7.克重8.固有频率9.两片罐10.脆值二、TrueorFalse(判断题)(20points)：(在题号前写T或F)1.MichiganStateUniversityofUSAwasthefirstuniversityrunningpackagingprogramintheworld(1952).2.Typically,theinform/sellfunctionplaysalesssignificantroleinindustrialpackaging.3.TheinternationalfiberboardcasecodeofRegularSlottedContainer(RSC)is#02104.AccordingtoMckeeformula,thecompressionstrengthofaRSCisrelatedtoMullenbursttest.5.Singlewallreferstotwosheetsoflinerboardwithonemediumsinbetween.6.TheobjectiveofStep3’CalculateCushionRequirement’istogainthemosteconomicalcushioningtoprovideadequateprotectionforbothshockandvibration.7.Iftheg-factorisestimatedtoohigh,theproductwillbeover-packaged.8.Thesofterthecushion,thelargertheGm(Gm—themaximumaccelerationordecelerationexperiencedbytheproduct).9.Theinterlockstackisbetterthancolumnstackintermsofstackstrength.10.PVDChasgottheexcellentbarrierpropertiestobothmoistureandoxygen.三、Questions(回答题)(15points)：(用中文或英文回答)1.Statethepackagingfunctions.2.Whatisasepticpackaging?3.SaytwotypesofpapermakingmachinesinChinese.4.IfECTofasingle-wallcorrugatedfiberboardboxis32lbs/in,howheavytheboxandcontentswillbelimited?5.Whatisthedifferencebetweenwet-bondlaminatinganddry-bondlaminating?四、MultipleChoices(单选题)(30points)：PartAChoosetheONEword/phrasewhichcouldbesubstitutedfortheunderlinedpartwithoutchangingthemeaningofthesentence.1.Thedecisionsofvariousretailingassociationscanalsohaveamajorimpactonpackaging.a.shockb.bearingc.vibrationd.part2.Someanimalproteinproductscandeterioratewithhours.a.spoilb.enlargec.appeard.disappear3.However,bysellingtotheworld,amanufacturingfacilitybecomesviable.a.usefulb.uselessc.availabled.flourishing4.Cropsandanimalhusbandryaremovedtowheretheirproductionismosteconomicalwithoutregardtotheproximityofamarket.a.distanceb.presencec.absenced.vicinity5.Inless-developedcountries,consumersarehappytohavefood,regardlessofthepackage.a.inspiteb.irrespectivec.despited.because6.Thisdiscussionhasreferredtoprimitivepackagingandtheevolutionofpackagingfunctions.a.improvementb.futurec.developmentd.idea7.Developingpackagingandlabelingtomeetdozenofdifferentwastemanagementsituationwouldbeprohibitive.a.costlyb.bannedc.preventedd.conditional8.“Plastics”embracesabroadspectrumofsyntheticmaterials.a.speciesb.kindc.gamutd.part9.Theconsumerpackageisapackagethatwillultimatelyreachtheconsumerasaunitofsalefromamerchandisingoutlet.a.thenb.eventuallyc.readilyd.easily10.Theprimarypackagemaybestrongenoughtoprotecttheproductandabletowithstandtherigorsofshipping.a.accommodateb.adaptc.endured.support11.Theinform/sellfunctionplaysalesssignificantroleinindustrialpackaging.a.featureb.partc.actiond.function12.Consumersinmostothercountriesdonothaveanaversiontobeefthatisnotbrightred.a.likeb.lovec.disliked.haveaninclinationto13.Inadditiontobiologicalaction,fattytissueissusceptibletooxidation.a.sensitiveb.allergicc.inertd.active14.AtpHlevelsabove4.5,conditionsareconducivetothegrowthofclostridiumbotulinum.a.harmfulb.undesirablec.beneficiald.unfit15.Despitetheseadvantages,NorthAmericanshavenotreadilyacceptedretortpouching.a.alreadyb.wellc.commonlyd.easily16.Theatmosphereusedmustbetailoredspecificallytothefooditemandthetypeofpackagebeingused.a.cutb.suitedc.adoptedd.applied17.Multiplefrictioncansareprimarilyusedbythepaintindustry.a.heavilyb.totallyc.importantlyd.firstly18.Thedisadvantagesofglassareitshighweightanditsbreakability.a.durabilityb.fragilityc.toughnessd.weakness19.Inreality,thechoiceinplasticsisalmostlimitless.a.Asthematteroffactb.Nearlyc.Virtuallyd.Generally20.Bakelitewaslargelydisplacedbythenewerthermoplasticsinthe1960s.a.changedb.supersededc.convertedd.disconnectedPartBQuestions21to30arebaseduponthepassagesfrom‘7.FillingByCount’onthepage241totheendonthepage244inyourtextbook:(下面10个选择题基于课本第241页的‘7.FillingByCount’到第244页的内容)21.Onadisccountertheproductbinisnearerthea.topofthediscb.centerofthediscc.bottomofthedisc22.Onadisccountertheitemsarecountedbybrushingthemintoa.cavitiesinthediscb.holesinthediscc.columnsunderthedisc23.Thenumberofproductitemsdeliveredbyadisccountertypefillerisdeterminedbya.thenumberofholesinthediscb.thenumberofcavitiesinthediscc.thesizeofthediscd.thespeedofrotation24.Onslatcountertypefillersthenumberofitemsineachfilliscontrolledbycountingthea.numberofslatsthatpassb.numberofholesc.numberofrowsthatareused25.Slatcountertypefillerarea.alwaysintermittentmotionb.alwayscontinuousmotionc.eitherintermittentorcontinuousmotion26.Vibratorsareusedonslatcountersfora.settlingtheproductintothecavitiesintheslatsb.shakingtheproductoutoftheslatsc.removingexcessproduct27.Columntypecounterscountertheproductbya.sensingthepresenceofeachitemb.measuringtheheightofthestackc.countingthenumberofcarriers28.Electroniccountertypefillerscounterthenumberofproductitembya.sensingeachitemb.measuringtheheightifthestackc.countingbygroupsd.shakingtheitemthroughholesinaplate29.Aloosetrayin