through switching key

例句：

1. 1. The engineer used a through switch to bypass the circuitry in the middle of the building.
   工程师使用一个通过开关来绕过建筑中间的电路。
2. 2. The technician found the through switch and quickly rerouted the power to the new system.
   技术员找到了通过开关，并迅速将电源重新路由到新系统。
3. 3. During maintenance, the technician had to use a through switch to access the electrical panel without disconnecting the main powersource.
   在维护期间，技术员不得不使用通过开关来访问电气板，而不断开主电源源。