| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a brief period | 60 |
|
| 2 | [prep] a brief period | 60 |
|
| 3 | for a brief period | 41 |
|
| 4 | for a brief period | 41 |
|
| 5 | after a brief period | 9 |
|
| 6 | after a brief period | 9 |
|
