| easily | 7 | manner |
| underground | 5 | location |
| always | 5 | temporal |
| gas → be → stored | 101 |
| gas → used with → a storage system | 4 |
| gas → be held in → storage | 3 |
| gas → be put into → storage | 3 |
| gas → be stored for → use | 3 |
| negative | neutral | positive |
| 0.191 | 0.660 | 0.149 |
| Raw frequency | 114 |
| Normalized frequency | 0.653 |
| Modifier score | 0.760 |
| Perplexity | 374.151 |