| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adv] [is] [prep] | 846 |
|
| 2 | [is] necessary [prep] | 524 |
|
| 3 | [adv] necessary [prep] | 451 |
|
| 4 | [adv] [is] necessary | 10 |
|
