| more efficiently | 9 | manner |
| from certain gases | 9 | other |
| to operate | 6 | purpose |
| engine → burn → fuel | 34 |
| engine → burn → the fuel | 7 |
| negative | neutral | positive |
| 0.379 | 0.456 | 0.165 |
| Raw frequency | 41 |
| Normalized frequency | 0.454 |
| Modifier score | 0.950 |
| Perplexity | 217.150 |