| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | by a [noun] | 18470 |
|
| 2 | [prep] a period | 2137 |
|
| 3 | [prep] a period | 2137 |
|
| 4 | by [art] period | 38 |
|
| 5 | by [art] period | 38 |
|
| 6 | by a period | 37 |
|
| 7 | by a period | 37 |
|
