单项选择题
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.
A.purifies
B.combinations
C.concentrations
D.filters
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相关考题
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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.
A.account as
B.account for
C.account to
D.account of -
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.
A.steps
B.procedures
C.precautions
D.programs -
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.
A.well trained
B.in good luck
C.in good health
D.sufficiently rested
