| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] [pos pn] [noun sg] [prep] a period | 9 |
|
| 2 | [prep] [pos pn] [noun sg] [prep] a period | 9 |
|
| 3 | [prep] [pos pn] [noun sg] for a period | 5 |
|
| 4 | [prep] [pos pn] [noun sg] for a period | 5 |
|
