| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | have been [prep] [det] [noun] | 452 |
|
| 2 | must have been [det] [noun] | 50 |
|
| 3 | must have been [prep] [noun] | 39 |
|
| 4 | must have been [prep] [det] | 26 |
|
