直流电机的定子主要由( )、主极、换向极、补偿绕组及引出线等组成。
A.换向器
B.机座
C.电刷
D.电枢
参考答案:B
—Let’s go to the zoo next week.
—Why not go to the mountains? We can go there.
A.boating
B.hiking
C.swimming
D.shopping
试论合同自由的具体内容。