| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb pp] [prep] [art] period [prep] | 343 |
|
| 2 | [been] [vb pp] [prep] [art] period | 38 |
|
| 3 | [been] [vb pp] [prep] [art] [prep] | 11 |
|
