| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | must have be [prep] [noun prp] | 9 |
|
| 2 | must [verb] been [prep] [noun prp] | 9 |
|
| 3 | must have be [prep] [noun prp] | 9 |
|
| 4 | must [vb infin] be [prep] [noun prp] | 9 |
|
