| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it must be [vb pp] that | 586 |
|
| 2 | it must [adv] be [vb pp] | 216 |
|
| 3 | must [adv] be [vb pp] that | 106 |
|
| 4 | it [adv] be [vb pp] that | 14 |
|
