| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adv] [prep] a long period | 25 |
|
| 2 | [adv] [prep] a long period | 21 |
|
| 3 | [adv] over a long period | 17 |
|
| 4 | [adv] over a long period | 17 |
|
