| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb -s] a [adj] duty [to-vb] | 23 |
|
| 2 | [vb -s] a [adj] duty [to-vb] | 23 |
|
| 3 | has a [adj] duty [to-vb] | 21 |
|
