series parallel switch

例句：

1. 1.The series parallel switch is used to control the flow of electricity.
   串联并联开关用于控制电流的流动。
2. 2. The series parallel switch was designed to improve the efficiency of the power system.
   串联并联开关被设计用来提高电力系统的效率。
3. 3. The series parallel switch was used to switch on and off the lights in the room.
   串联并联开关被用来在房间里打开和关闭灯。