| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it has been [vb pp] for [det] | 22 |
|
| 2 | it has be [vb pp] for some | 12 |
|
| 3 | it has be known for [det] | 12 |
|
| 4 | it has be [vb pp] for many | 9 |
|
