A combination combustible gas and oxygen indicator is an instrument that measures the（） of both combustible gas and oxygen; each is indicated on a separate meter.

Deficiencies in the categories of Life-saving, Safety i...

单项选择题Deficiencies in the categories of Life-saving, Safety in General, Fire-fighting Appliances and Load Line （） approximately 66% of all deficiencies.

All engineer officers and engine room ratings shall be ...

单项选择题All engineer officers and engine room ratings shall be aware of the serious effects of operational or accidental pollution of the marine environment and shall take all possible（） to prevent such pollution, particularly within the framework of relevant international and port regulations.

Duties shall be so organized by the chief engineer offi...

单项选择题Duties shall be so organized by the chief engineer officer that the first watch at the commencement of a voyage and the subsequent relieving watches are （） and otherwise fit for duty.