单项选择题
A.seal water supply be cut off B.make-up water supply be cut off C.oil outlet valve closed or not open sufficiently D.the flow rate of oil is too much
To ensure oil purifier working in normal condition,the ...
单项选择题To ensure oil purifier working in normal condition,the interval between two sludge discharging should not exceed（） hours.
Some refrigeration systems have chemical moisture indic...
单项选择题Some refrigeration systems have chemical moisture indicators installed in conjunction with the sight glass in the liquid lineIf excess moisture is present in the system, the indicator will （）
A.activate the driers B.change color C.secure the compressor D.add a predetermined amount of liquid drier
In the navigation, cause the shafting over load most ea...
单项选择题In the navigation, cause the shafting over load most easily（）
A.stopping the main engine suddenly B.changing the main engine running direction suddenly C.the sailing from the shallow water area to the deep water area D.the ship’s trim too much
