| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [noun pl] [verb] been studied [prep] [det] | 6 |
|
| 2 | [noun pl] have been study [prep] [det] | 6 |
|
| 3 | [noun pl] [vb base] been study [prep] [det] | 6 |
|
| 4 | [noun pl] have been study [prep] [det] | 6 |
|
