| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [pron] had been operating | 9 |
|
| 2 | [noun] had been operating | 8 |
|
| 3 | [noun sg] had been operating | 6 |
|
| 4 | had been operating [prep] | 8 |
|
| 5 | had been operating [prep] | 8 |
|
