| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adv] [prep] a period [prep] | 93 |
|
| 2 | [prep] a short period [prep] | 91 |
|
| 3 | [adv] [prep] a short period | 25 |
|
| 4 | [adv] a short period [prep] | 10 |
|
