| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [noun sg] [prep] a long period of | 50 |
|
| 2 | [noun sg] over a long period [prep] | 37 |
|
| 3 | [noun sg] of a long period [prep] | 8 |
|
| 4 | [noun sg] for a long period [prep] | 6 |
|
