| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [is] difficult [verb] [noun] | 142 |
|
| 2 | [is] [verb] such [noun] | 43 |
|
| 3 | difficult [verb] such [noun] | 21 |
|
| 4 | [is] difficult [verb] such | 14 |
|
