vacuum lead

例句：

1. 1. The vacuum tube was the first electronic device invented by Edison.
   真空管是爱迪生发明的第一个电子装置。
2. 2.The vacuum circuit is used to transmit signals over long distances.
   真空电路用于在远距离传输信号。
3. 3. The vacuum tube is still widely used in modern electronic devices.
   真空管在现代电子设备中仍然广泛使用。