| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adv] a long period | 43 |
|
| 2 | [adv] a long period | 41 |
|
| 3 | over a long period | 34 |
|
| 4 | [adv prt] a long period | 34 |
|
| 5 | over a long period | 34 |
|
| 6 | quite a long period | 8 |
|
| 7 | [adv] a long period | 8 |
|
| 8 | quite a long period | 8 |
|
