爆破警戒解除信号是()。浏览:497 爆破警戒解除信号是()。 A.一次长声,鸣30sB.一次长声,鸣60sC.一长一短,鸣30s,间隔,鸣20sD.一短一长,鸣10s,间隔,鸣20s正确答案:一次长声,鸣60s