A.0.5 B.1.0 C.1.5 D.2.0
A.間斷鳴三次長聲,即鳴30s、停、鳴30s、停、鳴30s B.間斷鳴一長、一短三次,即鳴20s、鳴10s、停、鳴20s、鳴10s、停、鳴20s、鳴10s C.連續(xù)三短聲,即鳴10s、停、鳴10s、停、鳴10s D.一次長聲,鳴60s