| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | is [adv] [verb] | 48380 |
|
| 2 | is necessary [verb] | 1322 |
|
| 3 | is [adv] necessary | 1024 |
|
| 4 | [adv] necessary [verb] | 780 |
|
