| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | be caused [prep] [adj] [noun pl] | 106 |
|
| 2 | may be [prep] [adj] [noun pl] | 50 |
|
| 3 | may be caused [prep] [adj] | 19 |
|
| 4 | may be caused [prep] [noun pl] | 5 |
|
