Then, Mrs.Parmele was writing math equations on the blackboard, I heard a familiar sound coming from the hallway.A voice I knew was singing the birthday song.

• 接着，正当帕姆勒太太往黑板上书写数学方程式的时候，我听到走廊里传来了一个熟悉的声音，那个熟悉的声音在唱生日快乐歌。