| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [verb] [art] long period of | 17 |
|
| 2 | [verb] a long period of | 16 |
|
| 3 | [vb pp] [art] long period of | 6 |
|
| 4 | [verb] the long period of | 6 |
|
| 5 | [vb past] [art] long period of | 5 |
|
| 6 | [verb] [art] longer period of | 5 |
|
