| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | must [verb] been [det] [noun] | 50 |
|
| 2 | [verb] been at [det] [noun] | 41 |
|
| 3 | must [verb] at [det] [noun] | 16 |
|
| 4 | must [verb] been at [det] | 5 |
|
