| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | which must [vb infin] been [adj] | 19 |
|
| 2 | which must have been [adj] | 19 |
|
| 3 | which must have been [adj] | 19 |
|
| 4 | which must [verb] been [adj] | 19 |
|
| 5 | which must [verb] been [adj] | 14 |
|
