| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | there must have been [det] | 47 |
|
| 2 | there must have [been] [det] | 47 |
|
| 3 | there must have [been] some | 24 |
|
| 4 | there must have [been] many | 18 |
|
