| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | and [prep] a [adj] period of | 7 |
|
| 2 | and for a [adj] period of | 5 |
|
| 3 | and [prep] a [adj] period of | 5 |
|
| 4 | and for a [adj] period of | 5 |
|
