单项选择题 The Oil Record Book, as a part of the ships official logbook, shall be kept on board and preserved for a period of （）.

单项选择题 Enhanced procedures concerning the exercise of （） have been developed to allow intervention in the ease of deficiencies deemed to pose a danger to persons, property or the environment.

单项选择题 It is often necessary to put an engine into （） service with one or more cylinders cut out, or with a turbocharger secured.