| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a longer period | 86 |
|
| 2 | [prep] a period [conj] | 49 |
|
| 3 | a longer period [conj] | 19 |
|
| 4 | [prep] a longer [conj] | 8 |
|
