| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb mod] have [been] caused by a | 9 |
|
| 2 | [vb mod] have [been] caused by a | 9 |
|
| 3 | [vb mod] have [been] caused by a | 9 |
|
| 4 | [vb mod] have been caused by a | 9 |
|
| 5 | may have [been] caused by a | 5 |
|
