【简答题】
A、间断鸣三次长声,即鸣30s、停、鸣30s、停、鸣30s B、间断鸣一长、一短三次,即鸣20s、鸣10s、停、鸣20s、鸣10s、停、鸣20s、鸣10s C、连续三短声,即鸣10s、停、鸣10s、停、鸣10s D、一次长声,鸣60s
A、间断鸣三次长声,即鸣30s、停、鸣30s、停、鸣30s B、间断鸣一长、一短三次,即鸣20s、鸣10s、停、鸣20s、鸣10s、停、鸣20s、鸣10s C、连续三短声,即鸣10s、停、鸣10s、停、鸣10s D、一次长声,鸣60s