直流电动机的转子组成主要有（）
A.电枢铁心
B.换向器
C.换向极
D.电枢绕组
E.轴和风扇
参考答案：A, B, D, E
When he was asked about the question where he was last night, he was _____. [ ]
A. at loss
B. in a loss
C. at a loss
D. with losses
活血散瘿汤功效与作用
