| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | have [vb pp] over a long period | 12 |
|
| 2 | [verb] [vb pp] over a long period | 12 |
|
| 3 | has [vb pp] over a long period | 5 |
|
| 4 | [vb -s] [vb pp] over a long period | 5 |
|
