| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | have [been] for [adv] | 30 |
|
| 2 | have [been] operate for | 15 |
|
| 3 | have [been] operate [adv] | 14 |
|
| 4 | [been] operate for [adv] | 7 |
|
