| while earlier | 7 | temporal |
| for using pcr primers | 4 | purpose |
| further | 3 | degree |
| sample → be → checked | 71 |
| sample → be → screened | 56 |
| negative | neutral | positive |
| 0.121 | 0.791 | 0.088 |
| Raw frequency | 127 |
| Normalized frequency | 0.510 |
| Modifier score | 0.936 |
| Perplexity | 406.610 |