| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | has [been] a [adj] | 1908 |
|
| 2 | [been] undergoing a [adj] | 7 |
|
| 3 | has [been] undergoing [adj] | 7 |
|
| 4 | has [been] undergoing a | 6 |
|
