| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it is necessary [to-vb] | 1050 |
|
| 2 | it is necessary for | 104 |
|
| 3 | is necessary [to-vb] for | 18 |
|
| 4 | it is [to-vb] for | 11 |
|
