| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] [adv] a long period | 6 |
|
| 2 | [prep] [adv] a long period | 6 |
|
| 3 | [adv] [prep] a long period | 25 |
|
| 4 | [adv] [prep] a long period | 25 |
|
| 5 | [adv] over a long period | 17 |
|
| 6 | [adv] over a long period | 17 |
|
| 7 | [adv] [verb] a long period | 6 |
|
