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| 代码区 | |||
| 编码区 | |||
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code area : 40 phrases in 15 subjects |
| Agriculture | 1 |
| Air defense | 1 |
| Aviation | 6 |
| Business | 3 |
| Communications | 1 |
| Desert science | 1 |
| Earth sciences | 1 |
| Economics | 1 |
| Electronics | 4 |
| General | 3 |
| Geology | 1 |
| Librarianship | 1 |
| Public security | 2 |
| Technology | 8 |
| Telecommunications | 6 |