| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | and [prep] a period of time | 9 |
|
| 2 | and [prep] a period of time | 9 |
|
| 3 | and [prep] a period of time | 9 |
|
| 4 | and over a period of time | 7 |
|
| 5 | and over a period of time | 7 |
|
