| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [verb] been concerned [prep] this | 6 |
|
| 2 | have been concerned [prep] this | 6 |
|
| 3 | been concerned [prep] this [noun] | 6 |
|
| 4 | been concerned [prep] this [noun sg] | 6 |
|
