 |
| élimination des poussières: 9 phrases in 4 subjects |
| Engines | 3 |
| Mining | 1 |
| Natural resourses and wildlife conservation | 3 |
| Technology | 2 |
|
| élimination des poussières: 9 phrases in 4 subjects |
| Engines | 3 |
| Mining | 1 |
| Natural resourses and wildlife conservation | 3 |
| Technology | 2 |