manual telephone exchange
常见例句
- A standard element of technology that can be traced to 1878 and the invention of the manual telephone exchange, the jack is apparently going the way of the floppy disk and the folding map.
这一标准技术元素可追溯至1878年，来自人工电话交换系统。 它似乎正在步入软盘和折叠地图的后尘。 返回 manual telephone exchange