| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a long period [prep] | 179 |
|
| 2 | during a [adj] period [prep] | 30 |
|
| 3 | during [art] long period [prep] | 15 |
|
| 4 | during a long [noun] [prep] | 13 |
|
