| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | difficulties in [verb] [prep] the [adj] | 7 |
|
| 2 | difficulties in [verb] [prep] the [adj] | 7 |
|
| 3 | difficulties in [v-ing] [prep] the [adj] | 7 |
|
| 4 | difficulties in [verb] [prep] the [adj] | 7 |
|
