| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | which [vb past] been formed [prep] [noun] | 8 |
|
| 2 | which had been formed [prep] [noun] | 8 |
|
| 3 | which [vb past] been formed [prep] [noun prp] | 7 |
|
| 4 | which [vb past] been formed in [noun] | 6 |
|
