雨课堂学堂在线学堂云《Dental Anatomy and Physiology（西安交通）》单元测试考核答案

第1题DentalAnatomyandPhysiologymainlystudiesthenormalmorphologicalstructures,functionalactivitiesandclinicalapplicationsoftheoralcavity.

第1题TheaimofthecourseDentalAnatomyandPhysiologyistoexplaintheanatomiclayersandorganmorphologyoftheoralcavity,skull,faceandneck,toidentifytheirstructuralcharacteristics,andtomastertheruleoftheirfunctionalactivities,soastolayasolidfoundationforthestudyandpracticeoftheclinicalmedicinecoursesinstomatology.

第2题Thebasicmethodologyforthelearningofthiscourseinclude：AfocusonpracticeBbegoodatsummarizing

CconsolidatetheknowledgeDalloftheabove第3题Thebasicviewofthissubjectis:Atheviewofevolutionarydevelopment

BtheviewofintegrationbetweenformandfunctionCtheholisticviewofhumanbody

Dalloftheabove第4题Thebasiccontentofthissubjectis:

AanatomyandphysiologyofteethB

localanatomyoforalcavity,maxillofacialregionandneckCdentition,occlusionandjawpositionDoralfunction正确答案：ABCD第5题ThefourthMedicalUniversity,SichuanUniversity,PekingUniversity,ShanghaiJiaotongUniversityandWuhanUniversityhavemadegreatcontributionstothedevelopmentoforalanatomyandphysiologyinChina.

Unit1test第1题Practicequestions第1题Theshapeofteethevolvedfromisodonttoheterodont.第2题Thenumberofteethchangesfromlesstomore.

Practicequestions第1题

Clinicalcrownscanbelargerorsmallerthananatomicalcrowns.第2题Whichofthefollowingtissuescanbeseeninthelongitudinalsectionofthecrown:AenamelBdentinCpulpDcementum正确答案：ABCPracticequestions第1题Whichtoothpositiondoes24standfor?

AmaxillaryleftfirstpremolarBmaxillaryrightfirstpremolarCmandibularrightfirstpremolarDmandibularleftfirstpremolar第2题Whichtoothpositiondoes73standfor?AdeciduousmaxillaryleftcanineBmaxillaryrightcanineCdeciduousmandibularleftcanineDdeciduousmandibularrightcaninePracticequestions第1题

Whichofthefollowingdescriptionsofthephysiologicalcharacteristicsoftootheruptionisincorrect:

AEruptionhappensinacertainorderBTheleftandrightcounterpartsareinpairsanderuptatthesametimeCThemandibularteethprecedetheirmaxillarycounterpartsineruptionDThemandibularteethprecedetheirmaxillarycounterpartsineruptionETheupperandlowercounterpartseruptsimultaneously正确答案：E第2题Thepermanentteeththatfirsteruptinthemouthanddonotreplaceanyprimaryteethare:ACentralincisors

BLateralincisorsCCaninesDFirstpremolarsEFirstmolars

正确答案：EPracticequestions第1题TheheightofcontourreferstoAThemostconvexpointonproximalsurfacesofthecrownBThemostconvexpointontheocclusalsurfaceofthecrownCThemostconvexpointoneachaxialsurfaceofatoothDThemostconvexpointoneachsurfaceofthecrownPracticequestions第1题Marginalridgeislocated:AonthelingualsurfaceofthecrownBatthemesialanddistalmarginsofthelingualsurfacefortheanteriorteethCatthemesialanddistalmarginsofthelingualsurfacefortheanteriorteethandtheocclusalsurfaceofthecrownfortheposteriorteethDaroundthefossaontheocclusalsurfaceofthecrown第2题Theelevationsofthecrowninclude:AthecuspBthecingulumCthemamelonDtheridgeEthemalformedcentralcusp正确答案：ABCDPracticequestions第1题Thecrown-rootratioofthemaxillarycentralincisorsismostly:A1:2B1:1C2:1D3:1E1:3Practicequestions第1题Thereferencetodistinguishtherightandleftsideofmandibularcentralincisorsis:

Athemesio-incisalangleisnearlyarightangleBthemesialcontactareaisrelativelyclosetotheincisalangleCthedisto-incisalangleisanobtuseangleDthedistalcontactarea

isrelativelyfartotheincisalangleEthelongitudinaldepressiononthedistalsurfaceisrelativelydeeperthanthatonthemesial

surface正确答案：EPracticequestions第1题Whichofthefollowingdescriptionsofthemorphologicalcharacteristicsofthemaxillarycentralincisorisincorrect:

()AThetoothrootisinclinedtowardthedistal.

BThedistalsurfaceissmallerthanthemesialsurface.CThemesialsurfaceandthedistalsurfacearetriangular-shaped.DThecontactareaisatthemiddlethirdoftheproximalsurface.Practicequestions第1题Whichofthefollowingdescriptionsofthemaxillarycanineisincorrect:()AThelabialaxialridgeisonthelabialsurface.BThelingualaxialridgeisonthelingualsurface.CThecusptipisoffsettowardthedistal.DThecusptipisoffsettowardthemesial.EThecrosssectionofthetoothrootisanovaltriangle第2题Whichtoothhasaroottwicethelengthofthecrown,andtheshapeofthecrosssectionoftherootisovaltriangular?()AThemaxillarycentralincisorBThemandibularcentralincisorCThemaxillarycanineDThemandibularcanineEThemaxillaryfirstpremolarPracticequestions第1题Whichofthefollowingstatementsofmaxillaryfirstpremolariscorrect:（）AItisthesmallestamongallthepremolarsBThetoothrootismostlyfurcatedintobuccalrootandlingualrootatthemiddlethirdortheapicalthirdoftherootCTheocclusalsurfacecanhavethreecuspsDThebuccalcuspisoffsettowardthemesialENoneoftheaboveiscorrectPracticequestions第1题Whichofthefollowingstatementsaboutthemandibularsecondpremolariscorrect?

AThebuccalcuspistallandlarge,whilethelingualcuspissmall.BThelingualsurfacediffersconsiderablyfromthebuccalsurface.CThebuccalsurfaceiswiderthanthelingualsurface.DThedevelopmentalgrooveisshapedinH,Y,WformEIfthepremolarhastwolingualcusps,thelingualsurfaceiswiderthanthebuccalsurface.正确答案：E第2题Whichofthefollowingstatementsofmandibularfirstpremolarisincorrect?AItisthesmallestpremolar.BTheheightdifferencebetweenthebuccalcuspandlingualcuspisthelargest.CThereisatransverseridgeontheocclusalsurface.DThebuccalcuspisoffsettowardthedistal.EThereisacrescent-shapedbucco-cervicalridgeonit.Practicequestions第1题Whichofthefollowingdescriptionsofthemaxillaryfirstpremolarisincorrect:AThebuccaltipisoffsettowardthedistalBThemesialanddistalcontactareasareatthebuccalthirdtowardthemarginoftheocclusalsurface.CTheocclusalsurfaceishexagonalDThemesialcontactareaisatthemiddlethirdtowardthemarginoftheocclusalsurface,whilethedistalcontactareaisatthebuccalthirdtowardthemarginoftheocclusalsurface.Practicequestions第1题Thepermanentteeththateruptat6yearsoldanddon'treplaceanydeciduousteethare:

AcentralincisorsBlateralincisorsCcaninesDpremolarsEfirstmolars正确答案：E第2题Whichofthefollowingdescriptionsofthemaxillaryfirstmolarisincorrect:AThemesialcuspisthesmallest.BThemesialcuspisthelargest.CSometimesthere'sthefifthcusp.DTheobliqueridgecanbeseenfromtheocclusalaspect.EIthas3roots.Practicequestions第1题Thegroovethatgoesacrosstheocclusalsurfacetothelingualsurfaceiscalledthemesiolingualgroove.

第2题Themesialmarginalridgeofthemaxillaryfirstmolarislongerthanthedistalmarginalridge.Practicequestions第1题Whichtoothshowstwoandhalfcuspsonthebuccalsurface?

AMaxillaryfirstmolarBMandibularfirstmolarCMaxillarysecondmolarDMandibularsecondmolarEThirdmolars第2题Whichtoothhavethecross-shapeddevelopmentalgrooves？AMaxillaryfirstmolarBMandibularfirstmolarCMaxillarysecondmolarDMandibularsecondmolarEMandibularsecondpremolarPracticequestions第1题The

longest

triangular

ridge

on

the

occlusal

surface

of

the

mandibular

first

molar

is

the

triangular

ridge

of

the

disto-buccal

cusp.Practicequestions第1题Themorphologyofthedeciduousmaxillaryandmandibularsecondmolarsarebothsimilartothatofthepermanentfirstmolarsonthesamejaw.第2题Thedistalcuspofthedeciduousmandibularsecondmolarissmallerthanmesiobuccalcuspanddistalbuccalcusp.Practicequestions第1题Themesiodistaldiameterofthedeciduousmaxillarycentralincisorislongerthanitsincisocervicaldiameter.Practicequestions第1题Thecuspofthedeciduousmaxillarycanineisoffsettowardsthedistalandthemesialslopeislongerthanthedistalslope.Practicequestions第1题Comparedwiththepermanentfirstmolaronthesamejaw,whatcharacteristicdoesthedeciduoussecondmolarhave:()AThecrownofthedeciduoussecondmolarissmallerthanthatofthepermanentfirstmolar,andthecolorisbluish-white.BThecrownofthedeciduoussecondmolarissignificantlyconstrictednearthecervix,andisalsoconstrictedtowardstheocclusalsurface,withthecervicalregionlargerthantheocclusalregion.CThemesiobuccalcusp,distobuccalcuspanddistalcuspofdeciduousmandibularsecondmolarareofthesamesize.DOneithersideofthesamejaw,betweenthetwosimilarmolarsinthemesialanddistaldirections,thesmalleronetothemesialisthedeciduoussecondmolar.正确答案：ABCDPracticequestions第1题Theatrophyofthegingivafromthedirectimpactionofthefoodiscausedby()AtheirregularshapeofthecrownBthenormalcrestofcurvatureofthecrown.Ctheunder-contouringcurvatureofthecrownDtheover-contouringcurvatureofthecrownEnoneoftheabove第2题Thedisusedatrophyofthegingivafromthelackofthefoodmassageonthegingivaiscausedby()Athenon-contouringcurvatureofthecrownBtheover-contouringcurvatureofthecrownCtheunder-contouringcurvatureofthecrownDthenormalcrestofcurvatureofthecrownEtheirregularshapeofthecrownPracticequestions第1题Thedeciduousteethandthepermanentteetharesimilarintheshapeoftheirpulpcavities.Butproportionally,thedeciduousteethhavethesmallerpulpcavities,thinnerwallsandtallerpulphornsthanthepermanentteeth.第2题Whichofthefollowingdoesnotbelongtotherootsystem？ATherootcanalBTheintercanalanastomosesCThelateralbranchesofrootcanalDTheapicalramificationEThepulpcavityPracticequestions第1题Thetoothwiththesmallestpulpcavityis_________.

AmaxillarycentralincisorBmaxillarylateralincisorCmandibularcentralincisorDmandibularlateralincisorPracticequestions第1题Amongthepremolars,whichofthefollowingteethhasthehighestproportionofhavingdoublerootcanalsAMaxillaryfirstpremolarBMaxillarysecondpremolarCMandibularfirstpremolarDMandibularsecondpremolarPracticequestions第1题WhichofthefollowingdescriptionsaboutthepulpcavityofthemandibularfirstpremolarsisincorrectAThemesiodistaldiameterofthepulpchamberislargerthanthebuccolingualdiameter,andthebuccolingualdiameterislargerthantheheightofthepulpchamber.BTheroofofthepulpchamberisconcave.Thebottomoftheconcavityisnearlyatlevelwiththecervicalmargin.CTheheightofthelingualpulphornnearlyreachesthemiddlethirdofthecrown.DThepulphornsofbuccalcuspsanddistalcusparerelativelylow,andarelocatedatcervicalthirdofthecrownornearthecervicalline.EThedouble-rootcanalsaccountfor13%amongthemesialrootcanals.正确答案：EPracticequestions第1题WhichofthefollowingteethcanhaveC-shapedcrosssectionattherootcanal?AMaxillaryfirstmolarBMaxillarysecondmolarCMaxillarythirdmolarDMandibularfirstmolarEMandibularsecondmolar正确答案：EUnit2Test第1题1.Whichchoice(s)canhelpdifferentiatethemandibularleftandrightcentralincisors?AThemesio-incisalangleisapproximatelyrightangle.BThemesialcontactareaisclosetotheincisalangle.CThedisto-incisalangleisanobtuseangle.DThedistalcontactareaisfarfromtheincisalangle.EThelongitudinaldepressiononthedistalsurfaceoftherootisslightlydeeperthanthatofthemesialsurface.正确答案：E第2题Whichofthefollowingstatementsabouttheenamelis/arecorrect:AItishighlycalcifiedandisthehardesttissueamongthetoothtissues.B

Itiswhiteandtranslucent.CItcoversthecrown.DItcoverstheroot.ENoneoftheaboveistrue.正确答案：ABC第3题Whichofthefollowingstatementsaboutthedentinis/areincorrect:____?AItissofterthantheenamel.BItisbeneaththeenamelandcementum.CItiswhiteandglassy.DItsurroundsthepulpcavity.EItmakesupthebulkofthetooth.第4题Thesmallestteetharethe:()AmaxillarycentralincisorsBmandibularcentralincisorsCmaxillarylateralincisorsDmandibularlateralincisorsENoneoftheaboveistrue.第5题Thefirstpermanentteethtoeruptintheoralcavityandnottoreplaceanydeciduousteetharethe()AcentralincisorsBlateralincisorsCcaninesDfirstpremolarsEfirstmolars正确答案：E第6题Thecrown-rootratioofthecentralincisorsismostly:()A1:2B1:1C2:1D3:1E1:3第7题Theinclinedplanesonthecrownreferto:()ATheplanesthatmakeupthemarginalridge.BTheplanesthatmakeupthecusp.CTheplanesthatmakeuptheaxialridge.DTheplanesthatmakeuptheridges.ETheobliqueplanesofthecrown.第8题Thedevelopmentalgroovesonthecrownreferto:()ATheshallowgroovesformedbythefusionoftwolobesduringteethdevelopment.BThegroovesformedduringteethdevelopment.CThedefectivepartsoftheincompletecalcificationDTheshallowgroovesontheocclusalsurfaceofthecrownETheslenderdepressionsonthecrown第9题Theelevationsonthecrowninclude:()AthecuspsBthecingulumCthemamelonDtheridgesEthemalformedcentralcusp正确答案：ABCD第10题Whichofthefollowingdescriptionsaboutthemandibularsecondpremolarsis/arecorrect:()AThecervico-occlusalheightequalsapproximatelytothebuccolingualthicknessandthemesiodistalwidth.BThelingualsurfacediffersconsiderablyfromthebuccalsurface.CThesizeofthelingualsurfaceissimilartothatofthebuccalsurface.DThedevelopmentalgroovespatterncanbeHtype,Ytype,orUtype.EIfthepremolarhas2lingualcusps,itslingualsurfaceiswiderthanthebuccalsurface.正确答案：ACDE第11题Theanatomicalcrownrefersto:()Athepartoftoothexposedintheoralcavity.Bthepartoftoothcoveredbygums.Cthepartoftoothperformingmastication.Dthepartoftoothcoveredbydentin.Ethepartoftoothcoveredbyenamel.正确答案：E第12题Whichofthefollowingdescriptionsaboutthemandibularfirstpremolarsis/arecorrect:()ATheyarethesmallestpremolars.BTheheightdifferencebetweenthebuccalcuspandthelingualcuspisthelargest.CTherearetransverseridgesontheocclusalsurface.DThebuccalcuspisoffsettowardthedistal.EThereisacrescent-shapedbuccocervicalridge.正确答案：ABCE第13题Thelandmarkforlocatingtheparotidglandductopeningisusuallyatthecrownof:()AthemaxillaryfirstmolarBthemandibularfirstmolarCthemaxillarysecondmolarDthemandibularsecondmolarEthemaxillarythirdmolar第14题Whichofthefollowingdescriptionsofthemaxillaryfirstmolaris/arecorrect:()AFourcuspscanbeseenfromtheocclusalaspect.BFivecuspscanbeseenfromtheocclusalaspect.CSometimesthereisthefifthcusp.DTheobliqueridgecanbeseenfromtheocclusalaspect.EThetoothrootistrifurcated.正确答案：ACDE第15题Whichtoothhasthedevelopmentalgroovesshapedlikeacross:()AthemaxillaryfirstmolarBthemandibularfirstmolarCthemaxillarysecondmolarDthemandibularsecondmolarEthemandibularsecondpremolar第16题Whichofthefollowingdescriptionsaboutthemaxillarycaninesis/arecorrect:()AthelabialaxialridgeisonthelabialsurfaceBthelingualaxialridgeisonthelingualsurfaceCthecusptipisoffsettowardthedistalDthecusptipisoffsettowardthemesialEthetoothrootisflat正确答案：ABD第17题Thelandmarkforlocatingthementalforamenis:()AthemandibularcentralincisorBthemandibularlateralincisorCthemandibularcanineDthemandibularpremolarEthemandibularmolar第18题Whichtoothhasaroottwicethelengthofthecrown,withanovaltriangularshapeatthecrosssectionoftheroot:()AThemaxillarycentralincisorBThemandibularcentralincisorCThemaxillarycanineDThemandibularcanineEThemaxillaryfirstpremolar第19题Whichofthefollowingdefinitionsofthetoothrootiscorrect?()AIt’sthepartofthetooththatisfixedinthetoothsockets.BItsupportsthetooth.CIt’sthepartofthetooththatiscoveredbycementum.DIt’sthepartofthetooththatiscoveredbydentin.EIt’sthepartofthetooththatiscoveredbyperiodontalmembrane.第20题Whichofthefollowingdescriptionsaboutthemandibularcanineis/arecorrect:()ATherootisflat,rounded,andslender.BTherearelongitudinaldepressionsonthemesialanddistalsurfacesoftheroot.CThedistalslopeofthecuspisabouttwicethelengthofthemesialslope.DTheangleformedbythemesialslopeandthedistalslopeislargerthan正确答案：ABCD第21题Whichofthefollowingdescriptionsaboutthemaxillaryfirstpremolaris/arecorrect:()AItssizeisthelargestamongthepremolars.BTherearetwocuspsontheocclusalsurface.CTherecanbethreecuspsontheocclusalsurface.DIthasalabialaxialridgeandalingualaxialridge.EInmostcases,thetoothrootisdividedintothebuccalrootandthelingualrootatthemiddleorapicalthirdoftheroot.正确答案：ABE第22题Whichofthefollowingdescriptionsaboutthelobeisincorrect:()AThefusionofthelobesbecomesthedevelopmentalgroove.BThecalcificationcenterintoothdevelopmentiscalledthelobe.CEverylobedevelopsintoacusp.DMostteetharedevelopedfromfourlobes.ESometeetharedevelopedfromfivelobes.第23题Theterm“roottrunk”refersto:()Athethickandlongrootofthecanine.BthefurcatedrootCthepartoftherootbeforefurcationDthepartoftherootafterfurcationEtherootwhosecrosssectionisrounded第24题Whichofthefollowingdescriptionsofthepatternoftheeruptionoftoothisincorrect?()AEruptionhappenswithinacertainperiod.BEruptionhappensinacertainorder.CTheleftandrightcounterpartsareinpairsanderuptatthesametime.DThemandibularteethprecedetheirmaxillarycounterpartsineruption.EForthepermanenttooth,theeruptiontimeofmaleisslightlyearlierthanthatoffemale.正确答案：E第25题Thereasonforgingivalatrophyduetothedirectimpactfromfoodsis:()AThecrownhasnoconvexity.BTheshapeofthecrownisirregular.CTheconvexityofthecrownistoolittle.DTheconvexityofthecrownisnormal.ETheconvexityofthecrownistoomuch.正确答案：AC第26题Thereasonforgingivalatrophyduetothegingivalweaknessresultedfromthelackofmassagefromfoodis:()AThecrownhasnoconvexity.BTheconvexityofthecrownistoomuch.CTheconvexityofthecrownistoolittle.DTheconvexityofthecrownisnormal.ETheshapeofthecrownisirregular.第27题“Midline”refersto:()Aanimaginarylinedividingskullandfaceintotwoequalparts.Banimaginarylinecrossingbetweenthetwoeyes.CanimaginarylinedividingthedentalarchintotwoequalpartsDanimaginarylinedividingtheskullandfaceintotwoequalleftandrightparts.Ethesagittalsutureoftheskull第28题Whichofthefollowingmorphologicaldescriptionsaboutthelabialsurfaceofthecrownofthemaxillarycentralincisorisincorrect?()ATheoutlineofthelabialsurfaceistrapezoidal.BTheinciso-gingivaldiameterislargerthanthemesio-distaldiameter.CThemesialmarginislongandstraight,whilethedistalmarginisshortandconvex.DTherearethreetofourlongitudinaldevelopmentalgroovesonthelabialsurface.EThemesialincisalangleisapproximatetoarightangle,whilethedistalincisalangleisbluntandrounded.第29题Whichofthefollowingdescriptionsaboutthecervicallineisincorrect?()AThecervicalmarginiscurvedineachaxialplaneofthecrown.BThecervicallineonthelabialorbuccalsurfaceisanarcconvextotheincisaledgeorocclusalmargin.CThecervicallineonthemesialsurfaceisanarcconvextotheocclusalmargin.DThecervicallineonthedistalsurfaceisanarcconvextotheocclusalmargin.EThecervicallineonthelingualsurfaceisanarcconvextotheroot.第30题Whichpermanentteethresemblethedeciduousmandibularfirstmolars?()AthepermanentmandibularfirstmolarsBthepermanentmandibularsecondmolarsCthemandibularfirstbicuspidsDthemandibularsecondbicuspidsEThereisnopermanenttoothresemblingthedeciduousmandibularfirstmolars.正确答案：E第31题Whichofthefollowingdescriptionsabouttheincisorgroupisincorrect:()ATheincisorgrouphassingleroots.BTheoutlineofthelabialandlingualsurfacesistrapezoidal.CThemesialanddistalsurfacesaretriangular.DThecontactareaisatthemiddlethirdoftheproximalsurface.EThemaxillaryincisorislargerthanthemandibularincisor.第32题Whichofthefollowingpercentilesaboutthetwo-rootrateofthemaxillaryfirstbicuspidiscorrect?()A80%B60%C50%D95%E87%第33题Thephysicalsignificancethatthelabialsurfaceoftherootofamaxillaryanteriortoothislargerthanthelingualsurfaceis:()Atobecontinuouswiththewiderlabialsurfaceofthecrown.Btoresisttheexternalforcesfromaccidentalcollisions.Ctoresisttheforwardocclusalforce.Dtoaccommodatetheshapeofthealveolarprocess.Etocompensatethelargerexternaldiameterofthedentalarch.第34题Whichpermanentteethtendtosustaincongenitalmissing:()AThemaxillaryfirstmolarsBThemaxillarysecondmolarsCThemaxillary

central

incisorsDThemaxillary

lateral

incisorsEThemaxillary

canines第35题Thehighestpulphorninthemaxillaryfirstmolaris:()AMesialbuccalpulphornBMesiallingualpulphornCDistalbuccalpulphornDDistallingualpulphornEThepulphornbeneaththefifthtip第36题Thedistalcontactareaofthemaxillaryfirstmolarislocatedat:()AtheocclusalthirdBthejunctionbetweenthebuccalthirdandthemiddlethirdattheleveloftheocclusalthird.CthemiddlethirdattheleveloftheocclusalthirdDthemiddlethirdEThejunctionofthemiddlethirdandthelingualthirdattheleveloftheocclusalthird.正确答案：E第37题Whichofthefollowingstatementsaboutthedifferencesbetweenthemaxillarylateralincisorandthemaxillarycentralincisorisincorrect?()AThelabialsurfaceisnarrowerandmoreroundedBThelingualfossaisnarroweranddeeperCTheinclinationoftheincisalridgetowardthelingualfromthemesialtothedistalissmallerthanthatofthecentralincisorDThemesio-incisalangleislikeanacuteangle第38题Whichofthefollowingdescriptionsaboutthecrownmorphologyofthedeciduousmandibularfirstmolarisincorrect?()AThemesialmarginofbuccalsurfaceislongandstraight,whilethedistalmarginisveryshortandconvex.BThemesio-buccalcuspislargerthanthedisto-buccalcusp.CThedisto-lingualcuspislongandsharp,whilethemesio-lingualcuspisshortandsmall.DTheocclusalsurfaceisanirregularquadrilateral,withaveryshortmarginalridge.EThemesialsurfaceresemblesatrianglewiththecervicallineasitsbase.第39题Whichofthefollowingstatementsaboutthemorphologyofthedeciduoussecondmolarisincorrect?()AThecrownissmallandwhitish.BThecervicalpartofthecrownisclearlynarrowedwithaprominentcervicalridge.CThecrownnarrowsdownfromthecervicaltotheocclusal.DThesizeofthemesio-buccalcuspanddistalcusparenotthesameETheroottrunkisshort,withtheroottipspreadingout.第40题Whichofthefollowingstatementsaboutthemorphologyofthedeciduousanteriorteethisincorrect?()AThecolorisgrayishwhite,andthecrownisshort.BThecrowniswideandtherootisnarrow.CThecusptipofthedeciduousmaxillarycanineisoffsettowardthedistal.DThemarginalridgesonthelingualsurfaceofthedeciduousmandibularincisorareflatterthanthatofthepermanentincisor.EFromtheproximalaspect,thelabialandlingualcervicalridgesaremoreprominentthanthoseofthepermanentteeth正确答案：BD第41题Theso-called"inter-canalanastomoses"is:()Atheinterconnectingbranchesbetweenadjacentrootcanals.Bthesmallbranchesofrootcanal.Cthebranchperpendiculartothemainrootcanal.Dthemainrootcanalbranchrunningthroughthedentinandcementumuntilreachingperiodontalmembrane.ETherootcanalramifiesattherootapex.第42题Theresultoftheagingchangesofthepulpcavityis:()AThepulpcavitybecomessmallerandthepulphornismoreconvex.BThedistancebetweentheroofandthefloorofthepulpchamberdecreases.CThepulpchamberisenlargedandthepulphorndisappears.DThepulpchamberfloorisclosertotherootbifurcation.EThepulpcalcifiedintopulpcalculus.第43题Thedeciduousteeththatfalloffearliestare:()AthedeciduousmaxillarycentralincisorsBthedeciduousmandibularcentralincisorsCthedeciduousmaxillarylateralincisorsDthedeciduousmandibularlateralincisorsEthedeciduousmandibularcanines第44题Whichofthefollowingcomparisonsbetweenthemandibularlateralincisorandthemandibularcentralincisoriscorrect:()AThecrownofthemandibularlateralincisorisslightlywider.BThemesialanddistalmarginsofthemandibularlateralincisorsaresymmetrical.CThemesialanddistalcontactareasofthemandibularlateralincisorsareclosetotheincisalangle.DThemesio-incisalangleandthedisto-incisalangleofthemandibularlateralincisorsareapproximatelyequal.EThedepthofthelongitudinaldepressionsonthemesialanddistalsurfacesofthemandibularlateralincisoristhesame.第45题Whichofthefollowingmorphologicalcharacteristicsofthepulpchambersofyoungpermanentmaxillaryincisorsiscorrect?()AThemesio-distaldiameterneartheincisalridgeisthelargest.BThemesio-distaldiameternearthecervicalmarginisthelargest.CThemesio-distaldiameterisnearlyequaltothelabiolingualdiameter.DThelabiolingualdiameterislargerthanthemesio-distaldiameter.EThelabiolingualdiameterislargerthantheinciso-gingivaldiameter.第46题Duringtheprocessofanimaldevelopmentfromthelowleveltothehighlevel,whichchangedidtoothevolutiongothrough?()AThenumberofteethchangedfromlesstomore.BThetoothshapechangedfromcomplex(heterodont)tohomodont(isodont).CThenumberofteethreplacementchangedfromdiphyodonttopolyphyodontandtomonophyodontDTheattachmentoftheteethonthejawbonechangedfromacrodonttopleurodontandthecodontETheattachmentoftheteethonthejawbonechangedfrompleurodonttoacrodontandthecodont第47题Whatisthetimeoftootheruption?()AThetimeofemergencefromthegingiva.BThetimeofcompleteeruptionofthecrown.CThetimewhenteethreachedocclusalcontact.DThetimewhenthecrownstartstomoveatthebonycrypt.EThetwothirdsofthecrowneruptiontime第48题Whichofthefollowingeruptionorderofthedeciduousteethiscorrect?()AⅠⅡⅤⅣⅢBⅠⅡⅢⅤⅣCⅠⅡⅣⅢⅤDⅤⅠⅡⅢⅣEⅠⅡⅤⅢⅣ第49题Duringthep