单项选择题
A.By cooling the oil below the ignition temperature B.By removing the fuel source from the fire C.By excluding the oxygen from the fire D.By increasing the weight of the oil
A.By backing down the track and cutting out ice on either bow B.By approaching from the stern and crossing ahead at an angle of 20° to 30° to the beset ship's course C.By overtaking the beset ship，running ahead and then backing down the track to the beset vessel D.By approaching the vessel from astern and towing the beset vessel stern first
A.It is faster B.It is slower C.There is no change D.It remains constant for varying propeller revolutions