| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | a limited period of time | 18 |
|
| 2 | a limited period [prep] time | 18 |
|
| 3 | a limited period [prep] time | 18 |
|
| 4 | a limited period [prep] time | 18 |
|
| 5 | a limited period [prep] time | 18 |
|
| 6 | a limited period of time | 18 |
|
