| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a brief period of | 13 |
|
| 2 | [prep] a brief period of | 13 |
|
| 3 | [prep] a brief period of | 13 |
|
| 4 | for a brief period of | 5 |
|
| 5 | for a brief period of | 5 |
|
