单项选择题
A.crane B.hatch cover C.windlass D.steering gear
Due to the large amount of heat picked up by the air in...
单项选择题Due to the large amount of heat picked up by the air in boiler and engine rooms, it would be （） to maintain ambient conditions within the comfort zone by air conditioning.
A.possible B.necessary C.practicable D.impracticable
A(n) （） is a mechanical attack on the metal surface whi...
单项选择题A(n) （） is a mechanical attack on the metal surface which may be due to a disturbance in the flow of the water over the blade of the propeller.
A.erosion B.corrosion C.pitting D.dezincification
A (n) （） is a chemical or electro-chemical attack on th...
单项选择题A (n) （） is a chemical or electro-chemical attack on the metal surface which may be further increased if the sea-water is polluted.
A.erosion B.corrosion C.cavity D.scouring
