水银开关

例句：

1. 1. The old house had a mercury switch that was difficult to operate.
   这所旧房子有一个难以操作的水银开关。
2. 2. The mercury switch in the circuit breaker is faulty.
   电路断路器中的水银开关有故障。
3. 3. The mercury switch was replaced with a modern electronic switch.
   将水银开关替换为现代电子开关。