| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it must have [been] [prep] for | 5 |
|
| 2 | it must have [been] [prep] for | 5 |
|
| 3 | [pron] must have [been] [prep] for | 5 |
|
| 4 | [pers pn] must have [been] [prep] for | 5 |
|
