| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | must have been [num] [prep] [det] | 5 |
|
| 2 | must have be [num] [prep] [det] | 5 |
|
| 3 | must have be [num] of [det] | 5 |
|
| 4 | must have be one [prep] [det] | 5 |
|
