单项选择题
Records of garbage disposal are required to be maintained （）.
A.until each quadrennial PSC inspection B.until the end of each voyage C.for a minimum of one year D.for a minimum of two years
单项选择题 The use of sinking and dispersing agents for the removal of surface oil is （）.
单项选择题 One of the disadvantages of using carbon dioxide to extinguish a fire in an enclosed space is （）.
单项选择题 A fire involving aluminum powder would be a class （）.
