| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it must [verb] been [prep] | 83 |
|
| 2 | it [verb] been [num] [prep] | 46 |
|
| 3 | must [verb] been [num] [prep] | 40 |
|
| 4 | it must [verb] been [num] | 26 |
|
