 |
| |||
| S 接口 (ISDN 的 TA 与 NT2 之间的接口，或 TE1 与 NT2 之间的接口) | |||
| S-interface: 8 phrases in 5 subjects |
| Air defense | 2 |
| Electronics | 3 |
| Information technology | 1 |
| Metallurgy | 1 |
| Technology | 1 |
|
| |||
| S 接口 (ISDN 的 TA 与 NT2 之间的接口，或 TE1 与 NT2 之间的接口) | |||
| S-interface: 8 phrases in 5 subjects |
| Air defense | 2 |
| Electronics | 3 |
| Information technology | 1 |
| Metallurgy | 1 |
| Technology | 1 |