| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | must [verb] be [prep] [det] | 26 |
|
| 2 | [modal v] [verb] be at [det] | 13 |
|
| 3 | must [verb] be at [adj] | 6 |
|
| 4 | must [verb] [be] at [det] | 5 |
|
