单项选择题
A.A vessel engaged in underwater operations
B.A vessel engaged in mine clearance
C.A vessel engaged on pilotage duty
D.A vessel engaged in survey operations
单项选择题 Which organization would conduct a survey of the insulation in a reefer compartment prior to loading cargo? （）
单项选择题 When a marine surveyor is employed to assist in the move of a mobile offshore drilling unit，he（）.
单项选择题 Refrigeration machinery is often surveyed before loading reefer cargo. This survey is usually performed by the（）.