| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | to a [adj] period [prep] | 20 |
|
| 2 | to a [adj] period of | 18 |
|
| 3 | to a [adj] period of | 18 |
|
| 4 | to a [adj] period [prep] | 17 |
|
| 5 | to a long period [prep] | 5 |
|
