| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [verb] [prep] a long period | 91 |
|
| 2 | [prep] a long period [conj] | 28 |
|
| 3 | [verb] [prep] a long [conj] | 26 |
|
| 4 | [verb] [prep] a period [conj] | 15 |
|
