A.沖擊 B.碰撞 C.拉拖 D.翻滾
A.間斷鳴三次長(zhǎng)聲,即鳴30s、停、鳴30s、停、鳴30s B.間斷鳴一長(zhǎng)、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(zhǎng)聲,鳴60s