| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | should have [been] at | 21 |
|
| 2 | should [vb infin] [been] at | 21 |
|
| 3 | should [vb infin] [been] at | 21 |
|
| 4 | should [vb infin] been at | 21 |
|
