| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a long period | 391 |
|
| 2 | [prep] a long period | 305 |
|
| 3 | over a long period | 232 |
|
| 4 | for a long period | 101 |
|
| 5 | [prep] a longer period | 86 |
|
| 6 | after a long period | 22 |
|
| 7 | of a long period | 12 |
|
| 8 | from a long period | 5 |
|
| 9 | to a long period | 5 |
|
| 10 | during a long period | 5 |
|
