| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | is necessary [verb] the [adj] [noun pl] | 15 |
|
| 2 | is necessary [verb] [art] [adj] [noun pl] | 15 |
|
| 3 | is necessary [to-vb] [art] [adj] [noun pl] | 15 |
|
