| |||
automatic switching of telegraph and telephone |
电话自动 交换 : 43 phrases in 12 subjects |
Business | 1 |
Electronics | 8 |
Exhibitions | 1 |
General | 2 |
Hydroelectric power stations | 3 |
Information technology | 1 |
Metallurgy | 1 |
Oil / petroleum | 1 |
Space | 1 |
Technology | 20 |
Telecommunications | 3 |
United Nations | 1 |