1主语+was/weredoingwhen...2主语+was/wereabouttodowhen...3主语+had/hadn'tdoneforsometime各举一个例子吧

　　1主语+was/weredoingwhen...2主语+was/wereabouttodowhen...3主语+had/hadn'tdoneforsometime

　　各举一个例子吧