| to understanding the topic | 21 | purpose |
| to all of the design components | 14 | transitive-object |
| to extraordinary progress by a civilization | 7 | other |
| concept → be → key | 89 |
| concept → be → the key | 28 |
| concept → become → key | 4 |
| negative | neutral | positive |
| 0.065 | 0.559 | 0.375 |
| Raw frequency | 121 |
| Normalized frequency | 0.577 |
| Modifier score | 0.400 |
| Perplexity | 32.229 |