| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [coord] it [is] [not/n't] known how | 5 |
|
| 2 | [coord] it [is] not known [Wh adv] | 5 |
|
| 3 | [coord] it is [not/n't] known [Wh adv] | 5 |
|
