| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a [adj] period [prep] | 773 |
|
| 2 | [vb pp] [prep] a [adj] period | 266 |
|
| 3 | [vb pp] [prep] a period [prep] | 232 |
|
| 4 | [vb pp] [prep] a [adj] [prep] | 139 |
|
| 5 | [vb pp] [prep] [adj] period [prep] | 44 |
|
| 6 | [vb pp] a [adj] period [prep] | 21 |
|
