| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adv] long period [prep] | 29 |
|
| 2 | [adv] long period of | 26 |
|
| 3 | [adv] long period [prep] | 24 |
|
| 4 | very long period [prep] | 10 |
|
| 5 | very long period [prep] | 10 |
|
| 6 | relatively long period [prep] | 5 |
|
| 7 | relatively long period [prep] | 5 |
|
| 8 | [adv] longer period [prep] | 5 |
|
