D

Grown-upsareoftensurprisedbyhowwelltheyremembersomethingtheylearnedaschildrenbuthaveneverpracticedeversince.Amanwhohasnothadachancetogoswimmingforyearscanstillswimaswellaseverwhenhegetsbackinthewater.Hecangetonabicycleaftermanyyearsandstillrideaway.Hecanplaycatchandhitaballaswellashisson.Amotherwhohasnotthoughtaboutthewordsforyearscanteachherdaughterthepoemthatbegins"Twinkle,twinkle,littlestar"orrememberthestoryofCinderellaorGoldilocksandtheThreeBears.

Oneexplanationisthelawofoverlearning,whichcanbestatedasfollows:Oncewehavelearnedsomething,additionallearningtrialsincreasethelengthoftimewewillRememberit

Inchildhoodweusuallycontinuetopracticesuchskillsasswimming,bicycleriding,and

playingbaseballlongafterwehavelearnedthem.Wecontinuetolistentoandremind

ourselvesofwordssuchas"Twinkle,twinkle,littlestar"andchildhoodtalessuchas

CinderellaandGoldilocks.Wenotonlylearnbutoverlearn.

Themultiplicationtables(乘法口诀表)areanexceptiontothegeneralrule.thatwe

forgetratherquicklythethingsthatwelearninschool,becausetheyareanotherofthethings

weoverlearninchildhood.

::ThelawofoverleatningexplainswhycrammingJ(突击学习)foranexamination,though

itmayresultinapassinggrade,isnotasatisfactorywaytolearnacollegecourse.Bycramming,astudentmaylearnthesubjectwellenoughtogetbyontheexamination,butheislikelysoontoforgetalmosteverythinghelearned.Alittleoverlearning,ontheotherhand,isreallynecessaryforone'sfuturedevelopment.

67.What‘themainideaofParagraph1

A.Peoplerememberwellwhattheylearnedinchildhood.

B.Childrenhaveabettermemorythangrown-ups.

C.Poemreadingisagoodwaytolearnwords.“

D.Storiesforchildrenareeasytoremember.

68.Theauthorexplainsthelawofoverlearningby

A.presentingresearchfindings

B.settingdowngeneralrules

C.makingacomparison

D.usingexamples

69.Accordingtotheauthor,beingabletousemultiplicationtablesis