单项选择题 For means of abandonment of a ship，which type of embarkation does not require prior approval by the Coast Guard?（）

单项选择题 For H2S detection，sensitized tapes indicate H2S presence by means of discoloration of an exposed spot on the tape. The shade of the color on the spot depends upon the concentration of H2S and（）.

单项选择题 For an OSV not on an international voyage，an approved substitute for an impulse projected type line throwing appliance is a（）.