| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | there have been many study | 6 |
|
| 2 | there have been many study | 6 |
|
| 3 | [ex0] have been many study | 6 |
|
| 4 | [pron] have been many study | 6 |
|
| 5 | have been many study [prep] | 5 |
|
| 6 | have been many study of | 5 |
|
| 7 | have been many study of | 5 |
|
| 8 | have been many study [prep] | 5 |
|
