| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | what [is] required [prep] | 69 |
|
| 2 | what is required [prep] | 69 |
|
| 3 | what [is] required of | 31 |
|
| 4 | what [is] required in | 12 |
|
| 5 | what [is] required for | 9 |
|
| 6 | what [is] required by | 6 |
|
