| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb pp] a long period [prep] | 9 |
|
| 2 | [vb pp] a long period [prep] | 9 |
|
| 3 | [vb pp] a long period of | 5 |
|
| 4 | [vb pp] a long period of | 5 |
|
| 5 | [verb] [vb pp] a long period | 5 |
|
| 6 | have [vb pp] a long period | 5 |
|
| 7 | [vb pp] [prep] a long period | 67 |
|
| 8 | [vb pp] [prep] a long period | 67 |
|
| 9 | [vb pp] over a long period | 44 |
|
| 10 | [vb pp] over a long period | 44 |
|
| 11 | [vb pp] for a long period | 14 |
|
| 12 | [vb pp] for a long period | 14 |
|
