| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a long [noun] | 3907 |
|
| 2 | [prep] a [adj] period | 1796 |
|
| 3 | [prep] a [adj] period | 1646 |
|
| 4 | [prep] a long period | 391 |
|
| 5 | [prep] [art] long period | 324 |
|
| 6 | [prep] [art] long period | 324 |
|
| 7 | [prep] a long period | 305 |
|
