OnedaywhileshoppinginasmalltowninsouthernCalifornia,itwasmymisfortunetobeapproachedbyaclerk.Heseemedmostunfriendlyandnotatallconcernedaboutmyintendedpurchase.Iboughtnothing,andmarchedangrilyoutofthestore.Ontheoutsidewasadark-skinnedyoungmaninhisearlytwenties.Hisexpressivebrowneyesmetandheldmine,andinthenextinstantabeautiful,brightsmilecoveredhisface.Igaveinimmediately.Thepowerofthatbroadsmiledissolvedallbitternesswithinme,andIfeltthemusclesinmyownfacehappilyresponding."Beautifulday,isn'tit?"Iremarked,passing.ThenIturnedback."Ireallyoweyouadebtofthanks,"Isaidsoftly.Hissmiledeepened,buthemadenoattempttoanswer.AMexicanwomanandtwomenwerestandingnearby.Thewomansteppedforwardandvolunteered,"Sir,buthedoesn'tspeakEnglish.Doyouwantmetotellhimsomething?"InthatmomentIfelttransformed.Theyoungman'ssmilehadmadeabigpersonofme.Myfriendlinessandgoodwilltowardallmankindstandtenfeettall.“Yes,”myreplywasenthusiasticandsincere,“tellhimIsaid,‘Thankyou!’”“Thankyou?”Thewomanseemedslightlypuzzled.IgaveherarmafriendlypatasIturnedtoleave."Justtellhimthat,"Iinsisted."He'llunderstand.Iamsure!"Oh,whatasmilecando!AlthoughIhaveneverseenthatyoungmanagain,Ishallneverforgetthelessonhetaughtmethatmorning.Fromthatdayon,Ibecamesmile-conscious,andIpracticetheartdiligentlyanywhereandeverywhere,witheverybody.(1).Whydidtheauthorleavethestoreangrily?A.Hecouldn'tbuywhathewanted.B.Theclerktreatedhimunkindly.C.Theclerkdidn'tspeakEnglish.D.Thestore'sgoodsweretoodear.(2).Bysaying"Ifeltthemusclesinmyownfacehappilyresponding"(inPara.2),theauthormeans_.A.hesmiledbackattheyoungmanB.hedidnotwanttosmileC.hewouldthanktheyoungmanD.hewasstillinabadmood(3).Theauthoraskedthewomantosay"Thankyou!"totheyoungmanbecausetheyoungman_.A.hadhelpedtheauthorbeforeB.taughttheauthorhowtosmileC.taughttheauthoravaluablelessonD.wasakindemployeeofthestore(4).Inthepassage,theauthorseemstosuggestthatweshould_.A.begeneroustostrangersB.practicesmilingeverydayC.helppeopleintroubleD.smileatotherpeople