| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | had been operate [prep] [art] | 7 |
|
| 2 | had been operating [prep] [art] | 7 |
|
| 3 | had been operate [prep] [art] | 7 |
|
| 4 | had been operate [prep] the | 5 |
|
| 5 | had been operate [prep] the | 5 |
|
