 |
| |||
| self-purification | |||
| self-cleaning | |||
| auto-épuration: 21 phrases in 4 subjects |
| Environment | 13 |
| Life sciences | 3 |
| Natural resourses and wildlife conservation | 4 |
| United Nations | 1 |
|
| |||
| self-purification | |||
| self-cleaning | |||
| auto-épuration: 21 phrases in 4 subjects |
| Environment | 13 |
| Life sciences | 3 |
| Natural resourses and wildlife conservation | 4 |
| United Nations | 1 |