| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | that [prep] the period | 50 |
|
| 2 | that in [art] period | 24 |
|
| 3 | that [prep] a period | 20 |
|
| 4 | that during [art] period | 20 |
|
| 5 | that over [art] period | 12 |
|
| 6 | that for [art] period | 6 |
|
