| for use in the present invention | 7 | purpose |
| particularly | 5 | degree |
| years ago | 3 | temporal |
| silica → be → necessary | 7 |
| silica → be → preferred | 4 |
| silica → be → adequate | 4 |
| silica → be → suitable | 3 |
| negative | neutral | positive |
| 0.090 | 0.457 | 0.452 |
| Raw frequency | 18 |
| Normalized frequency | 0.540 |
| Modifier score | 0.500 |
| Perplexity | 121.037 |