| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | have [be] operating for | 15 |
|
| 2 | have been operate for | 15 |
|
| 3 | have [be] operate for | 15 |
|
| 4 | have [been] operate for | 15 |
|
| 5 | have be operate for | 15 |
|
| 6 | has [be] operate for | 13 |
|
