| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | had been [prep] [noun] | 1251 |
|
| 2 | been used [prep] [noun] | 308 |
|
| 3 | had been used [prep] | 150 |
|
| 4 | had used [prep] [noun] | 20 |
|
