单项选择题
A.disengaging the clutch firstly, then stopping the main engine
B.stopping the main engine firstly, then disengaging the clutch
C.stopping the cooling water pump firstly, then stopping the main engine
D.stopping the main engine and disengaging the clutch at the same time
单项选择题 During the watch keeping at sea, the engineer in charge should notify in the event of any serious occurrence or a situation where he is unsure of the action to take（）
单项选择题 Before engaging the turning gear and turning the diesel engine, which of the following operation should be done except（）
单项选择题 The seven segment arrangement for numerical(数字的) display on consoles, test meters and other applications can be either（）