When the dock is refilled with water after docking repair, the first work which should be done by engineers is （）

A.the sinking of tail shaft
B.the clearance of stern bearing
C.the total flexure of both end bearing
D.main engine crankshaft deflection

A.the repair standard of main docking repair item
B.the special tool for repair item
C.the skill of repairer
D.the status of docking repair equipment

A.making the repair list, booking spare parts and special tools for the dock repair
B.shutting off all of the SW valves to outboard
C.the sketches or diagrams used for the dock repair
D.cleaning up the oil tank and boiler before enter the dock