| Similarity | Rank | |
|---|---|---|
| dioxide | 0.820 | 4762 |
| sulphur | 0.815 | 6647 |
| pollutant | 0.792 | 10281 |
| nox | 0.790 | 28969 |
| carbon | 0.765 | 3195 |
| monoxide | 0.757 | 12904 |
| co2 | 0.752 | 18793 |
| cfc | 0.750 | 9251 |
| ozone-depleting | 0.732 | 40272 |
| nitrogen | 0.731 | 6386 |
| particulate | 0.727 | 25930 |
| halon | 0.726 | 27495 |
| tetrachloride | 0.725 | 38419 |
| oxide | 0.722 | 7892 |
| chlorofluorocarbon | 0.720 | 24061 |
| hydrocarbon | 0.719 | 12320 |
| pollution | 0.718 | 2289 |
| nitrous | 0.709 | 29606 |
| ozone | 0.709 | 5037 |
| hcfc | 0.707 | 89263 |
| biofuel | 0.705 | 57289 |
| so2 | 0.705 | 62009 |
| ozone-damaging | 0.703 | 88642 |
| incineration | 0.700 | 18636 |
| &sub2; | 0.700 | 34174 |