X线中的最短波长指的是

A、电子接近原子核减速,丢失能量转换的X线光子
B、电子与原子核碰撞,全部能量转换的X线光子
C、电子与核外电子相碰,丢失能量转换的X线光子
D、电子击脱核内层电子,外层电子跃迁释放的X线光子
E、电子穿透原子与另外原子核作用,丢失能量转换的X线光子
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正确答案:

B

答案解析:

暂无解析

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TEXTC

Therearetwofactorswhichdetermineanindividual'sintelligence.Thefirstisthesortofbrainheisbornwith.

Humanbrainsdifferconsiderably,somebeingmorecapablethanothers.Butnomatterhowgoodabrainhehas

tobeginwith,anindividualwillhavealoworderofintelligenceunlesshehasopportunitiestolearn.Sothe

secondfactoriswhathappenstotheindividual—thesortofenvironmentinwhichheisbroughtup.Ifan

individualishandicapped(不利)environmentally,itislikelythathisbrainwillfailtodevelopandhewillnever

attainthelevelofintelligenceofwhichheiscapable.Theimportanceofenvironmentindetermininganindividual'sintelligencecanbedemonstratedbythecasehistoryoftheidenticaltwins,PeterandMark.Beingidentical,thetwinshadidenticalbrainsatbirth,andtheirgrowthprocesseswerethesame.Whenthetwinswerethreemonthsold,theirparentsdied,andtheywere

placedinseparatefoster(抚养)homes.Peterwasraisedbyparentsoflowintelligenceinanisolatedcommunity

withpooreducationalopportunities.Markwasrearedinthehomeofwell-to-doparentswhohadbeentocollege.Hewasreadtoasachild,senttogoodschools,andgiveneveryopportunitytobestimulated

intellectually.Thisenvironmentaldifferencecontinueduntilthetwinswereintheirlateteens,whentheywere

giventeststomeasuretheirintelligence.Mark'sI.Q.was125,twenty-fivepointshigherthantheaverageand

fullyfortypointshigherthanhisidenticalbrother.Givenequalopportunities,thetwins,havingidenticalbrains,

wouldhavetestedatroughlythesamelevel.

11.Thisselectioncanbestbetitled____________.

A.MeasuringYourIntelligence

B.IntelligenceandEnvironment

C.TheCaseofPeterandMark

D.HowtheBrainInfluencesIntelligence

12.Thebeststatementofthemainideaofthispassageisthat_______.

A.humanbrainsdifferconsiderably

B.thebrainapersonisbornwithisimportantindetermininghisintelligence

C.environmentiscrucialindeterminingaperson'sintelligence

D.personshavingidenticalbrainswillhaveroughlythesameintelligence

13.Accordingtothepassage,theaverageI.Q.is_______.

A.85.B.100C.110D.125

14.Thecasehistoryofthetwinsappearstosupporttheconclusionthat_______.

A.individualswithidenticalbrainsseldomtestatthesamelevelB.anindividual'sintelligenceisdeterminedonlybyhisenvironment

C.lackofopportunityblocksthegrowthofintelligence

D.changesofenvironmentproducechangesinthestructureofthebrain

15.Thispassagesuggeststhatanindividual'sI.Q._______.

A.canbepredictedatbirth

B.staysthesamethroughouthislife

C.canbeincreasedbyeducation

D.isdeterminedbyhischildhood

John'sscoreonthetestisthehighestintheclass;()helastnight.

A、muststudy
B、shouldhavestudied
C、musthavestudied
D、issuretostudy

Bysaying"thegrowthoftheproportion...toyoungergenerations."(Line2,Para.5),AntheaTinkerreallymeansthat________.

A、currentlywealthflowsfromoldgenerationtoyoungergeneration
B、traditionallywealthflowsfromyoungergenerationtooldgeneration
C、withtheincreasinglybigpopulationofover50,thetrendarisesthatwealthflowsfromyoungergenerationtooldgeneration
D、withmoreandmorepeopleofover50,traditionshavebeenreversed

Passage3

Questions11to15arebasedonthefollowingpassage:

UnliketheirAmericanorEuropeancounterparts,carsalesmeninJapanworkhardtogetabuyer.Insteadoflyinglazilyaroundshowroomswaitingforcustomerstodropby,manyJapanesecarsalesmenstillgoouttogetthem.Theywalkwearilyalongthestreetscarsdoor-to-door.Newcustomersarehuntedwithfruitandcakesontheirbirthdays.Butlifeisgettingtough,andnotjustbecausenew-carsalesarefalling.

WithmoreJapanesewomen(whooftencontrolthehouseholdbudget)goingouttowork,thesalesmenincreasinglyfindnobodyathomewhentheycall.Thatmeansanothervisitintheeveningortheweekend.Thentheyfaceanextraproblem:morepeople,especiallytheyoung,prefertochooseanewcarfromashowroomwheretheycancomparedifferentmodels.

Evenaslateasthemid-1980ssome90%ofnewcarsweresolddoor-to-door.Insomeruralareasmostnewcarsarestillsoldthisway.Butinthebigcitiesmorethanhalfthenewcarsarenowsoldfromshowrooms.

AlthoughinvestinginshowroomsisexpensivebecauseofthehighcostofJapaneseland,dealershavelittlechoice.AlaborshortageandhigheramongJapan’sworkforcearemakingitdifficulttohiredoor-to-doorsalesmen.MostofaJapanesecarsalesman’sworkingdayisspentdoingfavorsforcustomers,likearranginginsuranceorpickingupvehiclesforservicing,ratherthanactuallyselling.

Japan’sdoorstepcarsalesmenarenotabouttovanish.Thepersonalservicetheyprovideissodeep-rootedinJapanthattheyarelikelytooperatealongsidetheglitteringnewshowrooms.Thetwosystemsevencomplementeachother.Whatincreasinglyhappensisthattheshowroomattractstheinterestofapotentialbuyer,givingthefootsoresalesmenafirmleadtofollowupwithahomevisit.

11.Japanesecarsalesusuallydonotwaitatshowroomsforcustomerstodropby;instead,.

A.theysellcarsdoor-to-door

B.theybuypresentsfortheircustomers

C.theyenjoythemselvesinrecreationcenters

D.theygoouttodomarketresearches

12.Impliedbutstated:thecompetitionincarmarketis.

A.lightB.moderateC.fierceD.unfair

13.Youngpeopleliketobuyanewcar.

A.athomeB.fromashowroom

C.madeintheU.S.A.D.madeinJapan

14.ThesquadronofJapanesecarsalesmenisreducingbecauseof.

A.alaborshortage

B.higherexpectationsamongJapan’sworkforce

C.highcostland

D.bothAandB

15.Japanesecarsalesmentotheircustomersmanyfavorssuchas.

A.showingthemaroundinanexhibition

B.arranginginsurance

C.payingthemavisitonweekends

D.sellingolecarsforthem

The() inJanet‘scharacterhashinderedherfroomadvancementinhercareer.

A、weakness
B、merit
C、defect
D、shortcoming
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