| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | a period [prep] a [adj] years | 5 |
|
| 2 | [art] period [prep] a [adj] years | 5 |
|
| 3 | [art] period [prep] a [adj] years | 5 |
|
| 4 | a period [prep] a [adj] years | 5 |
|
