| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [is] [prep] [art] | 18581 |
|
| 2 | required [prep] [art] | 1462 |
|
| 3 | [is] required [prep] | 704 |
|
| 4 | [is] required [art] | 12 |
|
