| virtually continuously | 10 | manner |
| indefinitely | 8 | manner |
| without getting new fuel | 2 | other |
| fuel cell → can → operate | 13 |
| fuel cell → can → run | 11 |
| fuel cell → be able to → operate | 4 |
| fuel cell → can → work | 3 |
| negative | neutral | positive |
| 0.039 | 0.527 | 0.434 |
| Raw frequency | 31 |
| Normalized frequency | 0.469 |
| Modifier score | 0.500 |
| Perplexity | 299.116 |