| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | is [verb] [det] [noun] | 1295 |
|
| 2 | necessary [verb] [det] [noun] | 202 |
|
| 3 | is necessary [verb] [noun] | 146 |
|
| 4 | is necessary [verb] [det] | 98 |
|
