| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [noun] [prep] a long period | 137 |
|
| 2 | [noun sg] [prep] a long period | 102 |
|
| 3 | [noun] [noun sg] [prep] a long | 73 |
|
| 4 | [noun] [noun sg] [prep] a period | 61 |
|
