| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] [be] [art] | 24742 |
|
| 2 | must [be] [art] | 2272 |
|
| 3 | must [prep] [be] | 149 |
|
| 4 | must [prep] [art] | 88 |
|
