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| 改进的改进调频制 | |||
| 改进的改进型调频制; 改进的改进型调频制 (M2 FM) | |||
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| 双改良调频; 改进的改进型调频制 | |||
| modified-modified frequency modulation: 14 phrases in 9 subjects |
| Air defense | 1 |
| Earth sciences | 1 |
| Electronics | 3 |
| Geophysics | 1 |
| Information technology | 4 |
| Mathematics | 1 |
| Multimedia | 1 |
| Space | 1 |
| Telecommunications | 1 |