| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | over a long period [modal v] | 5 |
|
| 2 | over [art] long period [vb mod] | 5 |
|
| 3 | over [art] long period [modal v] | 5 |
|
| 4 | over a long period [modal v] | 5 |
|
