Have you found the woman ______purse was lost? [ ]
A. her
B. of which
C. that
D. whose
答案:D
凸轮轴凸轮磨损过限,对柴油机工作性能有何影响?
以下哪些过电压属于谐振过电压()
A.系统突然甩负荷产生的过电压
B.各相不对称断开时的过电压
C.电弧接地产生的过电压
D.开关断口电容与母线PT之间产生的过电压