| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb past] been [prep] | 4108 |
|
| 2 | been operate [prep] | 75 |
|
| 3 | [vb past] operate [prep] | 71 |
|
| 4 | [vb past] been operate | 33 |
|
