| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [verb] [prep] a long period | 91 |
|
| 2 | [verb] on [prep] a long | 49 |
|
| 3 | [verb] on [prep] a period | 6 |
|
| 4 | on [prep] a long period | 5 |
|
