| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a long period of [adj] | 16 |
|
| 2 | [prep] a long period of [adj] | 16 |
|
| 3 | of a long period of [adj] | 5 |
|
| 4 | of a long period of [adj] | 5 |
|
