ex.1 decide whether the sentence is correct or incorrect 1.Henry had worked as a rescue worker before he was retired in 1990 2.By 10a.m yesterday rescue workers had freed ten people trapped in the collapsed building 3.Mr jack was no longer there .He left the school six years before 4.The light went off because they hadn't pay the electricity bill 5.Hadn't she escaped before the walls collapsed in the earthquake?