| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | is [that] it [is] difficult | 12 |
|
| 2 | [is] that it [is] difficult | 12 |
|
| 3 | [is] [that] it [is] difficult | 12 |
|
| 4 | [is] [that] it is difficult | 8 |
|
