| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | and [prep] a period [prep] | 26 |
|
| 2 | and [prep] a period [prep] | 26 |
|
| 3 | and [prep] a period of | 23 |
|
| 4 | and [prep] a period of | 23 |
|
| 5 | and over a period [prep] | 12 |
|
| 6 | and for a period [prep] | 7 |
|
| 7 | and after a period [prep] | 7 |
|
