单项选择题
（）are located on the road panel of main switchboard.
A.Megohm meter, insulation light and synchroscope B.Synchroscope, synchro light and megohm meter C.Shore power switch, insulation light and synchroscope D.Megohm meter, insulation light and shore power switch
单项选择题 Insulation light is located on.（） of main switchboard.
单项选择题 Synchrocope and synchro light are located on （） of main switchboard.
单项选择题 To （） , the power is supplied by main switchboard directly not though sub-board.
