| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | must [vb infin] [prep] [art] | 1429 |
|
| 2 | [vb infin] [prep] [art] first | 276 |
|
| 3 | must [vb infin] [art] first | 18 |
|
| 4 | must [prep] [art] first | 9 |
|
