Peopleinthecitykepttheirsorroundings_______(protect).Theydon'tallowunknownpeople_______(invite)totheball.Ifoundastrangeperson_______(walk)nearbyourshopyesterday.Weheardthesong_______(sing)nextdoor.Weheardthem_______

　　Peopleinthecitykepttheirsorroundings_______(protect).

　　Theydon'tallowunknownpeople_______(invite)totheball.

　　Ifoundastrangeperson_______(walk)nearbyourshopyesterday.

　　Weheardthesong_______(sing)nextdoor.

　　Weheardthem_______(sing)nextdoorattimes.

　　Whenhegotoffthebus,hefoundhispocket_______(miss).

　　Hewasverydisappointed.Becausehefoundhimself_______(understand)difficultly.

　　Wenoticedagirl_______(seat)inachairbythewindow.

　　Thoughhehadoftenmadehislittlesister_______,todayhewasmade_______(cry)byhislittlesister.

　　Witheverything_______(buy),she left the supermarket with satisfaction.

　　分析原因!