A.一長(zhǎng)一短聲 B.一長(zhǎng)兩短聲 C.三長(zhǎng)聲 D.四長(zhǎng)聲
A.20m B.50m C.30m D.40m
A.鳴笛 B.開啟頭燈 C.減速運(yùn)行 D.長(zhǎng)聲鳴笛