单项选择题
A.Provides surface for applying force on machinery B.Provides landing surface for the sounding bob C.Absorbs machinery vibration D.Prevents valve stem over-travel
What is NOT used as a stern tube bearing，on a large ves...
单项选择题What is NOT used as a stern tube bearing，on a large vessel? （）
A.Wooden (lignum vitae) strips B.Hard rubber C.Resin bonded composition D.Bronze bushings
What best describes the structure from which Stratford ...
单项选择题What best describes the structure from which Stratford Point Light is shown?（）
A.Brown conical tower with white horizontal band in center of light on black pier B.Red conical tower on brown cylindrical pier C.White octagonal house on brown cylindrical pier D.White conical tower，with brown band midway of height
Upon underwater（）by divers，there are no apparent（）on th...
单项选择题Upon underwater（）by divers，there are no apparent（）on the bottom plates of the said vessel.
A.detection，defects B.defection，defects C.defects，defection D.defects，detection
