发电机并、解列前投入主变压器中性点接地隔离开关是为了有效限制（），保护绝缘。
参考答案：过电压
Paul's mother had him ________ because she couldn't bring him up herself.
A．adapted
B．adjusted
C．adopted
D．applied
靠电子导电的半导体叫空穴半导体，简称P型半导体。（）
