| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | been [verb] [art] | 5460 |
|
| 2 | been [v-ing] [art] | 2357 |
|
| 3 | [be] operating [art] | 59 |
|
| 4 | be operating [art] | 59 |
|
| 5 | [been] operating [art] | 8 |
|
| 6 | been operate [art] | 8 |
|
