| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [modal v] have been obvious to | 13 |
|
| 2 | [modal v] have been obvious to | 13 |
|
| 3 | [vb mod] have been obvious to | 13 |
|
| 4 | must have been obvious to | 5 |
|
| 5 | must have been obvious to | 5 |
|
| 6 | should have been obvious to | 5 |
|
| 7 | should have been obvious to | 5 |
|
