单项选择题
PassageOne Questions1to5arebasedonthefollowingpassage. WhenMrs.JosephGroegerdiedrecentlyinVienna,Austria,peopleaskedtheobviousquestion.“Whydidshelivetobe107”Answerswereprovidedbyasurveyconductedamong148Viennesemenandwomenwhohadreachedtheageof100.Whatwassurprisingwasthatthemajorityhadlivedmostoftheirlivesincities.Althoughcitiesareoftenregardedasunhealthyplaces,citylivingprovidesbenefitsthatcountrylivingmaylack.Onefactorseemstobeimportanttothelongevity(长寿)ofthoseinterviewed. Thisfactorisexercise.Inthecitiesitisoftenfastertowalkshortdistancesthantowaitforabus.Eventakingpublictransportationoftenrequiressomewalking.Smallerapartmenthouseshavenoelevators,andsopeoplemustclimbstairs.Citypeoplecanusuallywalktolocalsupermarkets.Sinceparkingspacesarehardtofind,thereisoftennochoicebuttowalk. Ontheotherhand,thosewholiveinthecountryandsuburbsdonothavetowalkeveryday.Infact,theoppositeisoftentrue.Togotoschool,work,oralmostanywhereelse,theymustrideincars.
We can draw a conclusion from this passage that（）
A．airpollutionisnotserious
B．anyonecanlivetobe107
C．countrypeopleshouldmovetocities
D．walkingisahealthfulexercise