| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a long period | 391 |
|
| 2 | [prep] a long and | 123 |
|
| 3 | [prep] long period and | 22 |
|
| 4 | a long period and | 14 |
|
| 5 | [prep] a period and | 12 |
|
