| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | so it must have be | 10 |
|
| 2 | so it must have [been] | 10 |
|
| 3 | so it must have [be] | 10 |
|
| 4 | so it must have been | 10 |
|
| 5 | so it must have [be] | 10 |
|
