| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | must have been [prep] [prep] | 12 |
|
| 2 | must have been [prep] [prep] | 12 |
|
| 3 | must have been like [prep] | 10 |
|
| 4 | must have been [prep] for | 8 |
|
