| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | may be required for | 19 |
|
| 2 | may be required by | 16 |
|
| 3 | may be required in | 13 |
|
| 4 | may be required as | 6 |
|
| 5 | may be required under | 5 |
|
| 6 | may be required to | 5 |
|
