Fire protection regulations for towing vessels allow all of these types of fuel piping，EXCEPT（）.

During the manufacture of line，yarns are twisted together in the（）.

Fighting a rig fire in the ballast pumproom with hoses would adversely affect the stability of the rig most by（）.

Each EPIRB required on an OSV shall be tested using the integrated test circuit and output indicator every（）.

Fire protection regulations apply to those towing vessels（）.

Fire extinguishers used on ship’s are numbered by size I through V，with I being（）.

During transfer operations，a quantity of propylamine spills on deck. According to the Chemical Data Guide，the correct procedure would be to（）.

Each hand portable，semi-portable and fixed fire extinguishing unit on a ship must be tested and inspected at least once every（）.

During the course of a voyage，a seaman falls on the main deck and injures his ankle. The Master should submit a Report of Marine Accident，Injury or Death if the（）.

Fire dampers prevent the spread of fire by（）.