单项选择题
The “urgent” priority should be used for messages（）.
A.concerning the Safety of Life at Sea (SOLAS) B.detailing important navigational warnings C.containing information concerning the safety of a mobile unit or person D.concerning on-scene communications
单项选择题 The “horse latitudes” are regions of（）.
单项选择题 One of the first actions to be taken by survivors when they have boarded an inflatable liferaft is to（）.
单项选择题 Normal pool elevation is the height in feet of the section of river above a dam. This height is measured from（）.
