| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [noun] must [prep] be | 7 |
|
| 2 | [noun] must [prep] been | 5 |
|
| 3 | [noun] must of [be] | 5 |
|
| 4 | [noun] must [prep] [been] | 5 |
|
