单项选择题 For each person it is certified to carry，a lifeboat on an oceangoing passenger vessel must be provided with all of the following EXCEPT（）.

单项选择题 Before hydraulic starting of an engine on a covered lifeboat，what need NOT be checked?（）

单项选择题 Aluminum lifeboats are subject to damage by electrolytic corrosion (the aluminum being eaten away). In working around boats of aluminum you must be very careful（）.