| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb past] been used [prep] [det] | 12 |
|
| 2 | had [been] used [prep] [det] | 12 |
|
| 3 | [vb past] [been] used for [det] | 6 |
|
| 4 | [vb past] [been] used [prep] many | 5 |
|
