A.prevent the seawater from intergrating
B.prevent the lube oil from running out of the outside aboard
C.strengthen the intencity of the sterntube
D.prevent the mud and sand from entering the lube oil system

A.on the sailing, the water in the aft peak tank should be excluded as much as possible
B.the stuffing style ahead sealing shouldn’t have any water leaking out
C.Simplex astern sealing shouldn’t have any oil leaking out
D.Simplex ahead sealing can have some oil leaking out

A.the good sealing performance and the simple structure
B.the good sealing performance and the short life expectancy
C.the good sealing performance but the short life expectancy
D.the good sealing performance and the lower cost

A.the shafting’s vertical vibration
B.violent friction and sea water corrosive
C.friction and high temperature
D.violent friction and high temperature

A.the border flange’s excursion and flection
B.the both end shafts line’s accordance
C.the border flange’s flection and the both end shafts line’s accordance
D.the border flange’s accordance and both end shafts flection degree

A.the stopping engine suddenly
B.the sailing astern and changing direction suddenly
C.the sailing from the shallow water area to the deep water area
D.the ship’s trim too much

A.after the thrust power is zero
B.after the torsion is zero
C.surpass the critical point on the water turbo phase
D.after the speed is zero

A.rapid reduction of ship’s friction force
B.shaft system over mechanical load
C.sharp growth of the torque of diesel engine
D.propeller torque change along J=0 curve

A.reduce the fuel feeding of main engine of inner propeller
B.reduce the fuel feeding of main engine of outer propeller
C.firstly reduce the fuel of main engine of inner propeller, then reduce the fuel feeding of engine of outer propeller
D.reduce fuel feeding of two engines at the same time

A.stop main engine immediately
B.ask the captain and the chief engineer’s permission for stopping the engine
C.initiatively inquire the bridge for the situation
D.stop engine and inform bridge

A.10%
B.15%
C.20%
D.5%