| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | be a long [noun] of | 92 |
|
| 2 | be a [adj] period of | 39 |
|
| 3 | be [art] long period of | 10 |
|
| 4 | [be] a long period of | 7 |
|
| 5 | be a long period of | 7 |
|
| 6 | be a long period [prep] | 7 |
|
| 7 | be a long period [prep] | 7 |
|
