单项选择题
The purpose of the commutator and brushes on a DC generator is to（）
A.change AC to DCcurrent B.change DC to AC current C.neutralize a armature reaction D.carry current to the outside circuit
单项选择题 DC generators are classified according to the manner in which（）
单项选择题 A circuit that has one wire in contact with the hull of the ship is a（）
单项选择题 If two AC generators are to be operated in parallel, the load is distributed evenly by（）
