单项选择题
A.the rotate speed fluctuation
B.the ventilation tube clogged
C.the main engine accelerate so fast
D.stormy waves
单项选择题 The tailshaft sealing arrangement found a little lube oil leaky and caused a lot of seawater into the bearing, the step should be taken as a makeshift is（）
单项选择题 When the vessel shafting are installed, the slightly inclined of the shaft line should be rectified by（）
单项选择题 Setting a sealing equipment astern on the tailshaft can’t （）