A.avoid kinking the hoseB.avoid personal injury during ……

单项选择题Which statement is TRUE concerning spare charges for portable fire extinguishers on unmanned tank barges?（）.

A.Spare charges shall be carried for at least 50 percent of each size and variety required on board
B.If the unit cannot be charged by the vessel's personnel，one spare unit shall be carried in lieu of spare charges
C.Spare charges shall be stowed in watertight containers on deck
D.Regulations concerning spare charges do not apply to unmanned barges

单项选择题A cabinet or space containing the controls or valves for the fixed firefighting system must be（）.

A.posted with instructions on the operation of the system
B.ventilated and equipped with explosion-proof switches
C.painted with red and black diagonal stripes
D.equipped with a battery powered source of emergency lighting