John's score on the test is the highest in the class ; （）he last night.
C
「句意」约翰的考试分数全班最高;他昨天晚上一定学习了。
「难点」表示对过去某一动作行为的猜测须要用musthavedone这一句型结构。
Our（）sensitivitydecreaseswithage.Byage60，mostpeoplehavelost40percentoftheirabilitytosmelland50percentoftheirtastebuds.
Toobtainasatisfactoryresult，onemustapplytwo____ofpaintonacleansurface.
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