| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] [v-ing] to the [adj] | 397 |
|
| 2 | difficulty [prep] [v-ing] the [adj] | 118 |
|
| 3 | difficulty [prep] [v-ing] to the | 13 |
|
| 4 | difficulty [prep] [v-ing] to [adj] | 8 |
|
