| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it [vb mod] be [verb] | 12232 |
|
| 2 | [vb mod] be necessary [verb] | 542 |
|
| 3 | it [vb mod] be necessary | 532 |
|
| 4 | it be necessary [verb] | 9 |
|
