| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it be [prep] [adj] period | 41 |
|
| 2 | it be [prep] [det] period | 40 |
|
| 3 | it be [prep] this period | 39 |
|
| 4 | it be [prep] this period | 39 |
|
| 5 | it was [prep] [adj] period | 34 |
|
| 6 | it be during [adj] period | 22 |
|
| 7 | it be in [adj] period | 9 |
|
| 8 | it is [prep] [adj] period | 7 |
|
