| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | must have [verb] at | 57 |
|
| 2 | must have [verb] at | 57 |
|
| 3 | must have [vb pp] at | 56 |
|
| 4 | must have looked at | 7 |
|
| 5 | must have look at | 7 |
|
