| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | period was [art] | 71 |
|
| 2 | period was the | 44 |
|
| 3 | period was the | 44 |
|
| 4 | period was a | 26 |
|
| 5 | period was a | 22 |
|
