| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | must be [verb] to be [adj] | 27 |
|
| 2 | must be [vb pp] to be [adj] | 27 |
|
| 3 | must be seen to be [adj] | 13 |
|
| 4 | must be see to be [adj] | 13 |
|
