| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | required [prep] be [verb] | 145 |
|
| 2 | be required [prep] be | 26 |
|
| 3 | be [prep] be [verb] | 18 |
|
| 4 | be required [prep] [verb] | 9 |
|
