| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | in a [adj] period [prep] | 30 |
|
| 2 | in a [adj] period [prep] | 29 |
|
| 3 | in a [adj] period of | 26 |
|
| 4 | in a [adj] period of | 26 |
|
| 5 | in a short period [prep] | 10 |
|
| 6 | in a short period [prep] | 9 |
|
