 |
| |||
| 定位道岔 | |||
|
normal switch : 7 phrases in 5 subjects |
| Air defense | 1 |
| Aviation | 1 |
| Communications | 1 |
| Rail transport | 1 |
| Technology | 3 |
|
| |||
| 定位道岔 | |||
|
normal switch : 7 phrases in 5 subjects |
| Air defense | 1 |
| Aviation | 1 |
| Communications | 1 |
| Rail transport | 1 |
| Technology | 3 |