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| explosive echo ranging | |||
| 爆炸回声测距: 6 phrases in 4 subjects |
| Earth sciences | 1 |
| Explosives and Explosive Ordnance Disposal | 1 |
| Navigation | 1 |
| Technology | 3 |
|
| |||
| explosive echo ranging | |||
| 爆炸回声测距: 6 phrases in 4 subjects |
| Earth sciences | 1 |
| Explosives and Explosive Ordnance Disposal | 1 |
| Navigation | 1 |
| Technology | 3 |