为加速症状的恢复,最好还应补充一些
A.维生素D
B.维生素C
C.维生素B2
D.维生素B6
E.维生素PP
参考答案:A
I _____ in Shanghai since I was a child. [ ]
A. used to live
B. lived
C. have lived
D. live
三相鼠笼式异步电动机Y接法AB两相定子全部烧坏,C相绕组正常原因是()。
A、过载;
B、C相电源中断;
C、AB两侧间短路