 |
| |||
| 人为活动 | |||
| 人类活动 | |||
| man's activity: 3 phrases in 3 subjects |
| Earth sciences | 1 |
| Explosives and Explosive Ordnance Disposal | 1 |
| Navigation | 1 |
|
| |||
| 人为活动 | |||
| 人类活动 | |||
| man's activity: 3 phrases in 3 subjects |
| Earth sciences | 1 |
| Explosives and Explosive Ordnance Disposal | 1 |
| Navigation | 1 |