| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [art] period of time [det] | 5 |
|
| 2 | [art] period of time [det] | 5 |
|
| 3 | a period of time [det] | 5 |
|
| 4 | a period of time [det] | 5 |
|
| 5 | period of time [prep] [det] | 5 |
|
| 6 | period of time [prep] [det] | 5 |
|
