Onceagroupof50peoplewasattendingaseminar(討論會).Halfwayth...
問題詳情：Onceagroupof50peoplewasattendingaseminar(討論會).Halfwaythrough 61 （he）talk,thespeakerstoppedanddecided 62 (create)agroupactivity.Hewentaroundthehallandgaveeachpersonaballoon.Eachonewasask...