单项选择题
The order “（）” means “Maximum maneuvering engine revolution for ahead propulsion”.
A.Full Ahead B.Half Ahead C.Full Astern D.Half Astern
单项选择题 The trim of a vessel is the （）.
单项选择题 The explosive range of a mixture of flammable vapors is specified as a percentage of （）.
单项选择题 What safety precautions should be observed by the crew while working around machinery in an engine room?（）
