Directions: There are 20 blanks in the following passage. For each blank there are four choices marked A, B, C and D. You should choose the ONE that best fits into the passage.There are two factors which determine an individual’s intelligence. The first is the sort of brain he is born 1) _________ .Human brains 2)__________considerably, some being more capable than others. But no matter how good a brain he has to begin with, an 3 )___________ will have a low order of intelligence4)_____________he has opportunities to learn. So the second factoris what 5)____________to the individual in the sort of environment in which he is brought6)__________ . If an individual is handicapped7)___________ , it is likely that his brainwill8)__________to develop and he will never 9)____________the level of intelligence of which he is 10 )___________ .The importance of environment in determining an individual’s intelligence can be 11)___________ by the casehistory of the identical twins, Peter and John. When the twins werethree months old, their parents died, and they were placed in12)___________foster （寄养）homes. Peter was13)______________by parents of low intelligence in an14)_____________community with poor educational15)______________ . John, however was educated in the home of well-to-do parents who had been to college. This environmental16 )______________ continued until the twins were 17)______________ their late teens,18)_______________they were given tests to 19)_____________ their intelligence. John’s I.Q.(智商) was 125, twenty-five points higher than the20)____________and fully forty points higher than his identical brother.1.A.forB.byC.withD.in2.A.changeB.differC.getD.grow3.A.individualB.personC.brainD.intellectual4.A.ifB.thoughC. asD.unless5.A.refersB.happensC.appliesD.concerns6.A.aboutB.upC.forwardD.forth7.A.relativelyB.intelligently C.relevantlyD.environmentally8.A.failB.helpC.manageD.stop9.A.surpriseB.attainC.failD.have10.A.ableB.capableC.availableD.acceptable11.A.demonstratedB.denied C.neglectedD.ignored12.A.separateB.similarC.remoteD.individual13.A. fearedB.broughtC.raisedD.cultivated14.A.omittedB.isolatedC.enclosedD.occupied15.A. capacitiesB.opportunitiesC. possibilitiesD.responsibilities16.A.exceptionB.divisionC.differenceD.alteration17.A.inB.onC.atD.for18.A.whileB.sinceC.whenD.because19.A.estimateB.countC.decideD.measure20. A.averageB.commonC.usualD.ordinary