| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it [is] necessary for us [verb] | 10 |
|
| 2 | [pers pn] [is] necessary for us [verb] | 10 |
|
| 3 | [pron] [is] necessary for us [verb] | 10 |
|
| 4 | it [is] necessary for us [verb] | 10 |
|
