| in an electron beam system | 6 | other |
| to those approaches | 5 | other |
| no longer | 2 | temporal |
| catalyst → be → required | 17 |
| catalyst → be → necessary | 14 |
| negative | neutral | positive |
| 0.104 | 0.642 | 0.254 |
| Raw frequency | 31 |
| Normalized frequency | 0.546 |
| Modifier score | 0.200 |
| Perplexity | 181.880 |