| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a [adv] long period of | 11 |
|
| 2 | [prep] a [adv] long period of | 11 |
|
| 3 | for a [adv] long period of | 6 |
|
| 4 | for a [adv] long period of | 6 |
|
| 5 | over a [adv] long period of | 5 |
|
| 6 | over a [adv] long period of | 5 |
|
| 7 | a [adv] long period of [noun] | 15 |
|
| 8 | a [adv] long period of [noun sg] | 15 |
|
| 9 | a [adv] long period of time | 13 |
|
| 10 | a [adv] long period of time | 13 |
|
