 |
| |||
| trackside signal | |||
| ground signals | |||
| ground signal | |||
| wayside signal; wayside signalling | |||
| 地面信号: 20 phrases in 12 subjects |
| Aviation | 1 |
| Communications | 2 |
| Construction | 1 |
| Electronics | 3 |
| Geophysics | 1 |
| Information technology | 1 |
| Oil / petroleum | 1 |
| Project management | 1 |
| Rail transport | 3 |
| Space | 2 |
| Technology | 3 |
| Telecommunications | 1 |