| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb mod] be [prep] [verb] | 595 |
|
| 2 | [vb mod] be required [verb] | 590 |
|
| 3 | [vb mod] be required [prep] | 278 |
|
| 4 | be required [prep] [verb] | 9 |
|
