| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | who [vb base] been at | 6 |
|
| 2 | who have [been] at | 6 |
|
| 3 | who [vb base] [been] at | 6 |
|
| 4 | who [vb base] [been] at | 6 |
|
