| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it must [verb] [verb] [prep] | 76 |
|
| 2 | it must [verb] [verb] [prep] | 76 |
|
| 3 | it [modal v] [verb] [verb] at | 37 |
|
| 4 | [pron] must [verb] [verb] at | 34 |
|
| 5 | it must [verb] [verb] at | 10 |
|
