单项选择题
One hour before sailing, the duty engineer and officer should check （）
A.tachometer and engine telegraph B.oil and water reserves C.clock and engine telegraph and test the rudder D.crews
单项选择题 When stand-by before sailing, the duty engineer and officer should check clock, engine telegraph and rudder, and then write it in the （）
单项选择题 （） is (are) not power supplied by main switchboard directly.
单项选择题 （）is power supplied by main switchboard directly not through sub-board.
