（）is （are） not power supplied by main switchboard directly

For _______the power is supplied by main switchboard directly not through sub-board

A.saving network cost

B.improving the reliability of supplying power to important load

C.preventing sequence reversing

D.increasing the power Factor of important load

A.Deck machinery

B.Little power load

C.Some important load machinery

D.Stationary submersible pump

B．励磁机、旋转整流器和主发电机

C．永磁式发电机、励磁机、旋转整流器和主发电机

D．发动机、附件齿轮箱、恒速传动装置和主发电机

B．高于固有频率时，电容器具有较小的容抗，回路具有RL串联电路特性

C．低于固有频率时，电感线圈有较大的感抗，回路具有RC串联电路特性

D．高于固有频率时，电感线圈有较小的感抗，回路具有RL串联电路特性