| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | have been [adj] studies | 23 |
|
| 2 | have been [det] study | 15 |
|
| 3 | have been few study | 6 |
|
| 4 | have been many study | 6 |
|
| 5 | have been many study | 6 |
|
| 6 | have been [adj] study | 6 |
|
| 7 | have been few study | 6 |
|
