一道大学英语阅读理解,请高手进来看看Today,asineveryotherdayoftheyear,morethan3000U.S.adolescents（青年人）willsmoketheirfirstcigaretteontheirwaytobecomingregularsmokersasadults.Duringtheirlifetime,itc

　　一道大学英语阅读理解,请高手进来看看

　　Today,asineveryotherdayoftheyear,morethan3000U.S.adolescents（青年人）willsmoketheirfirstcigaretteontheirwaytobecomingregularsmokersasadults.Duringtheirlifetime,itcanbeexpectedthatofthese3000about23willbemurdered,30willdieintrafficaccidents,andnearly750willbekilledbyasmoking-relateddisease.Thenumberofdeathsattributedtocigarettesmokingoutweighsallotherfactors,whethervoluntaryorinvoluntary,asacauseofdeath.

　　Sincethelate1970s,whendailysmokingamonghighschoolseniorsreached30percents,smokingratesamongyouthhavedeclined.Whilethedeclineisimpressive（印象深刻的）,severalimportantissuesmustberaised.

　　First,inthepastseveralyears,smokingratesamongyouthhavedeclinedverylittle.Second,inthelate1970s,smokingamongmalehighschoolseniorsexceededthatamongfemalebynearly10percent.Thestatisticisreversing.Third,severalrecentstudieshaveindicatehighschooldropoutshaveexcessivelyhighsmokingrates,asmuchas75percent.

　　Finally,thoughsignificantdeclinesinadolescentsmokinghaveoccurredinthepastdecade,nodefinitereasonsforthedeclineexist.Withinthiscontext,theNationalCancerInstitute(NCI)beganitscurrentefforttodeterminethemosteffectivemeasurestoreducesmokinglevelsamongyouth.

　　1、Accordingtotheauthor,thedeathsamongyoutharemainlycausedby_____.

　　单选题

　　A.A.trafficaccidents

　　B.B.smoking-relateddisease

　　C.C.murder

　　D.D.allofthese

　　2、Everydaythereareover_____highschoolstudentswhowillbecomeregularsmoker.

　　单选题

　　A.A.75

　　B.B.23

　　C.C.30

　　D.D.3000

　　3、By"dropout"theauthormeans______.

　　单选题

　　A.A.studentswhofailedtheexamination

　　B.B.studentswholeftschool

　　C.C.studentswholosttheirway

　　D.D.studentswhoweredrivenoutofschool

　　4、Thereasonfordecliningadolescentsmokingisthat________.

　　单选题

　　A.A.NCIhastakeneffectivemeasures

　　B.B.smokingispreventedamonghighschoolseniors

　　C.C.therearemanysmokerswhohavediedofcance