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| 自动数字跟踪 | |||
| automatic digital tracking: 11 phrases in 8 subjects |
| Air defense | 2 |
| Aviation | 1 |
| Earth sciences | 1 |
| Electronics | 1 |
| Mathematics | 1 |
| Space | 2 |
| Technology | 2 |
| Telecommunications | 1 |
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