| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | be necessary for [det] purpose | 10 |
|
| 2 | [be] necessary for [det] purpose | 10 |
|
| 3 | [be] necessary for [det] purpose | 10 |
|
| 4 | [be] necessary for that purpose | 6 |
|
