Learningtodriveisimportanttotheindependenceofteenagers，butitisalsoagreatresponsibility．Althoughhavingalawthatkeeps16-year-olddriversfromhavingmorethanoneteenagerinthecarwiththematfirstseemsunfair，therearec

　　Learningtodriveisimportanttotheindependenceofteenagers，butitisalsoagreatresponsibility．Althoughhavingalawthatkeeps16-year-olddriversfromhavingmorethanoneteenagerinthecarwiththematfirstseemsunfair，thereareconvincingreasonsforthisrequirement．

　　TheInsuranceInstituteforHighwaySafetyreportsthatteensarefourtimesmorelikelythanolderdriverstobeinvolvedinanautomobileaccident．Italsoreportsthat16-and17-year-olddriversaretwiceaslikelytohaveanaccidentiftheyhavetwoteenagefriendsinthecarandfourtimesaslikelytohaveoneiftheyhavethreeormoreteenagefriendsinthecarwiththem．Fatal（致命的）crashesof16-year-olddriversinvolvethehighestpercentageofspeeding，drivererror，andnumberofpassengers．Thisinformationisenoughtocauseanyreasonablepersontowonderaboutthewisdomofallowingnewteendriverstotakeacarloadoffriendsanywhere，evenifthelawpermitsit．

　　AstudyattheNationalInstitutesofHealthindicatesthatthepartofthehumanbrainthatcontrolsjudgmentandevaluatestheconsequencesofouractionsmightnotbefullyformeduntiltheageof25．Untilthisstudy，researchershadplacedtheageat18．Ifthisistrue，itcouldexplainthereckless（鲁莽的）behaviorofmanyteens，behaviorthatoftenextendsintotheirtwenties．Italsocouldbeastrongreasonforbeingcautiousaboutthedrivingcircumstancesofyoungpeople．

　　Thisisnottheonlystudythatindicatessuchcautionisnecessary．OnestudyatTempleUniversityinPhiladelphiaexaminestheresultsofpeerpressureinriskydrivingsituations．Thestudy，whichusesadrivinggame，hasanindividualguideacarthroughacourse，bothaloneandinthepresenceoffriends．Threedifferentagegroupsparticipatedinthestudy：13-16，18-22，and24andolder．Membersoftheoldestgroupshowedcautionwhetherdrivingaloneorwithfriendspresent，butthetwoyoungergroupstookmorechanceswhentheywerewiththeirfriends．Furthermore，becausethesedriverswereaccustomedtothenoiseanddistractionofmanypassengers，theywereunabletoseetheirownmistakes．Onceagain，thisisagoodindicationthatalawrestrictingthenumberofteenagersinthecarwithayoungdriverisagoodidea．

　　67．WhatdoestheauthormainlytellusinPara