| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [modal v] be required to be [verb] | 14 |
|
| 2 | [vb mod] be required to be [verb] | 14 |
|
| 3 | be required to be [verb] [prep] | 11 |
|
| 4 | be required to be [verb] [prep] | 11 |
|
