| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [verb] on [prep] a [adj] period | 9 |
|
| 2 | [verb] on [prep] a [adj] period | 8 |
|
| 3 | [verb] on [prep] a long period | 5 |
|
| 4 | [verb] on [prep] a period [prep] | 5 |
|
| 5 | [verb] on [prep] a period [prep] | 5 |
|
