单项选择题
A.approved by the Coast Guard
B.high carbon steel
C.fixed with a ferrous cover
D.nonsparking
单项选择题 Prior to entering a cargo pump room, you should ensure that （）.
单项选择题 Personnel who are moving or handling material aboard ship should NOT follow which of the listed practices?（）
单项选择题 Prior to starting most medium-speed propulsion diesel engines, which of the procedures listed should be observed?（）