单项选择题 The system of valves and cargo lines in the bottom piping network of a tank vessel that connects one section of cargo tanks to another section is called a（）.

单项选择题 The shipping papers for the products being carried in your tanker are NOT required to contain the（）.

单项选择题 The required number and type of hand portable fire extinguishers for staterooms on cargo vessels is（）.