单项选择题
To prevent damage by and to storage batteries aboardsmall passenger vessels they should be located（）.
A.in trays constructed of material that is resistant to the electrolyte B.so as to prevent movement when the vessel pitches and rolls C.in a well ventilated area D.All of the above
单项选择题 The vertical movement of a vessel in the water is called（）.
单项选择题 The time required to incline from bow down to stern down and return to bow down again is called（）.
单项选择题 The principal action in changing from transit to survival draft in the event heavy weather threatens is（）.
