| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a long period | 391 |
|
| 2 | [adv prt] [prep] a long | 212 |
|
| 3 | [adv prt] [prep] a period | 54 |
|
| 4 | [adv prt] a long period | 34 |
|
