| to understanding the history | 7 | purpose |
| during the industrial revolution | 5 | temporal |
| river → be → key | 19 |
| river → be → the key | 3 |
| negative | neutral | positive |
| 0.059 | 0.667 | 0.274 |
| Raw frequency | 22 |
| Normalized frequency | 0.346 |
| Modifier score | 0.500 |
| Perplexity | 431.120 |