| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [conj] a long period [prep] | 7 |
|
| 2 | [conj] a long period of | 6 |
|
| 3 | [conj] a long period of | 6 |
|
| 4 | [conj] a long period [prep] | 5 |
|
