| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | have been [adj] studies [prep] | 18 |
|
| 2 | have been [adj] [adj] studies | 10 |
|
| 3 | have been [adj] [adj] [prep] | 9 |
|
| 4 | been [adj] [adj] studies [prep] | 8 |
|
