 |
| |||
| 双声道; 双声迹; 双磁迹 | |||
|
dual track : 6 phrases in 6 subjects |
| Air defense | 1 |
| Aviation | 1 |
| Economics | 1 |
| Metallurgy | 1 |
| Rail transport | 1 |
| Technology | 1 |
|
| |||
| 双声道; 双声迹; 双磁迹 | |||
|
dual track : 6 phrases in 6 subjects |
| Air defense | 1 |
| Aviation | 1 |
| Economics | 1 |
| Metallurgy | 1 |
| Rail transport | 1 |
| Technology | 1 |