| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | to be a [adj] period [prep] | 5 |
|
| 2 | to [be] a [adj] period [prep] | 5 |
|
| 3 | to [be] a [adj] period [prep] | 5 |
|
| 4 | to be a [adj] period [prep] | 5 |
|
