单项选择题
The main advantage of improved Simplex tailshaft seal are（）
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
相关考题
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单项选择题
Simplex tailshaft seal equipment’s working condition is terribleThe main cause is （）
A.the shafting’s vertical vibration
B.violent friction and sea water corrosive
C.friction and high temperature
D.violent friction and high temperature -
单项选择题
The center line condition of the transmission shaft can be checked by（）
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 -
单项选择题
In the navigation（） cause the shafting over load easily.
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
