| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | have been shown to be | 176 |
|
| 2 | [vb -s] been shown to be | 100 |
|
| 3 | has been shown to be | 100 |
|
| 4 | [vb base] been shown to be | 62 |
|
| 5 | have been shown to be | 62 |
|
| 6 | [vb past] been shown to be | 13 |
|
| 7 | had been shown to be | 13 |
|
