| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | is [adj] [verb] [adj] [noun] | 1749 |
|
| 2 | be necessary [verb] [adj] [noun] | 283 |
|
| 3 | [be] necessary [verb] [adj] [noun] | 283 |
|
| 4 | [is] necessary [verb] [adj] [noun] | 131 |
|
