 |
| |||
| pollution control | |||
|
antipollution : 43 phrases in 12 subjects |
| Economics | 1 |
| Electronics | 1 |
| Environment | 16 |
| Finances | 1 |
| General | 9 |
| Isolation | 1 |
| Natural resourses and wildlife conservation | 2 |
| Natural sciences | 2 |
| Politics | 1 |
| Taxes | 1 |
| Transport | 6 |
| United Nations | 2 |