| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a [adj] period [v-ing] [prep] | 9 |
|
| 2 | [prep] a [adj] period [v-ing] [prep] | 9 |
|
| 3 | a [adj] period [prep] [v-ing] [prep] | 6 |
|
| 4 | a [adj] period [prep] [v-ing] [prep] | 6 |
|
| 5 | a [adj] period [v-ing] [prep] [art] | 5 |
|
| 6 | a [adj] period [v-ing] [prep] [art] | 5 |
|
| 7 | a [adj] period [v-ing] [prep] [noun] | 5 |
|
