| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | been a [adj] factor [prep] | 55 |
|
| 2 | have been a [adj] factor | 12 |
|
| 3 | have been a factor [prep] | 11 |
|
| 4 | have been a [adj] [prep] | 8 |
|
