| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | but it [be] necessary [to-vb] | 28 |
|
| 2 | but it be necessary [to-vb] | 28 |
|
| 3 | but it [is] necessary [to-vb] | 26 |
|
| 4 | but it is necessary [to-vb] | 24 |
|
