SS4型电力机车采用转向架牵引电机并联的（）调压整流电路。
参考答案：独立供电
既能治疗胸痹，又能治疗泻痢里急后重的药物是（）
A.瓜蒌
B.桂枝
C.薤白
D.枳实
E.厚朴
I got this bicycle for ____ .My friend gave it to me when she bought a new one. [ ]
A. everything
B. something
C. anything
D. nothing
