| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a [adj] period | 2001 |
|
| 2 | [prep] a [adj] to | 263 |
|
| 3 | a [adj] period to | 16 |
|
| 4 | [prep] [adj] period to | 9 |
|
