| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | necessary [to-vb] at the | 15 |
|
| 2 | necessary [to-vb] at [art] | 15 |
|
| 3 | necessary [to-vb] at the | 15 |
|
| 4 | necessary to look at [art] | 13 |
|
