| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb past] be in force | 15 |
|
| 2 | [vb past] been in force | 15 |
|
| 3 | had [be] in force | 15 |
|
| 4 | [vb past] [been] in force | 15 |
|
