| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a [adj] period [prep] | 773 |
|
| 2 | [prep] a very [adj] period | 52 |
|
| 3 | a very [adj] period [prep] | 50 |
|
| 4 | [prep] a very [adj] [prep] | 5 |
|
