| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | have become [art] [adj] problem | 13 |
|
| 2 | have become a [adj] problem | 13 |
|
| 3 | have become [art] [adj] problem | 13 |
|
| 4 | have become a [adj] problem | 10 |
|
| 5 | has become [art] [adj] problem | 9 |
|
