| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adv] a [adj] of | 884 |
|
| 2 | a [adj] period of | 842 |
|
| 3 | [adv] [adj] period of | 154 |
|
| 4 | [adv] a [adj] period | 58 |
|
| 5 | [adv] a period of | 37 |
|
