| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] [noun] [prep] a | 35609 |
|
| 2 | [noun] [prep] a period | 832 |
|
| 3 | [prep] [noun] [prep] period | 38 |
|
| 4 | [prep] [prep] a period | 6 |
|
