 |
| |||
| low medium frequency | |||
| |||
| low and medium frequency | |||
| 低中频: 18 phrases in 9 subjects |
| Air defense | 1 |
| Aviation | 4 |
| Construction | 1 |
| Electronics | 4 |
| General | 3 |
| Geophysics | 2 |
| Project management | 1 |
| Space | 1 |
| Technology | 1 |
|
| |||
| low medium frequency | |||
| |||
| low and medium frequency | |||
| 低中频: 18 phrases in 9 subjects |
| Air defense | 1 |
| Aviation | 4 |
| Construction | 1 |
| Electronics | 4 |
| General | 3 |
| Geophysics | 2 |
| Project management | 1 |
| Space | 1 |
| Technology | 1 |