| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adv] a long period of | 12 |
|
| 2 | [adv] [art] long period of | 12 |
|
| 3 | over [art] long period of | 8 |
|
| 4 | over [art] long period of | 8 |
|
| 5 | [adv prt] [art] long period of | 8 |
|
