单项选择题
All electrical appliances aboard a vessel should be grounded to（）.
A.prevent them from falling when the vessel rolls B.protect personnel from electrical shock C.increase their operating efficiency D.prevent unauthorized personnal from operating them
单项选择题 All entries in logbook,（）made,must not be erased or amended.
单项选择题 All entries in the official logbook must be signed by the master and（）.
单项选择题 All event relating to the voyage,such as ship’s position,speed and details of the weather, are recorded in（）.
