| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | must [vb infin] been full | 5 |
|
| 2 | must [vb infin] [been] full | 5 |
|
| 3 | must [vb infin] be full | 5 |
|
| 4 | must have [be] full | 5 |
|
