自动励磁调节时，发电机空负荷电压能在额定电压的70%～110%范围内稳定平滑的调节。
参考答案：对
It was April 29, 2011 ______ Prince William and Kate Middleton walked into the palace hall
of the wedding ceremony. [ ]
A. that
B. when
C. since
D. before
临床上以补气药配合止血药治疗出血证的理论基础是（）
A.气能行血
B.气能生血
C.气能摄血
D.血为气母
