| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | shown to [be] [adj] | 235 |
|
| 2 | shown to [be] [adj] | 227 |
|
| 3 | [verb] to [be] essential | 31 |
|
| 4 | [vb pp] to [be] essential | 13 |
|
| 5 | shown [prep] [be] essential | 5 |
|
| 6 | shown [prep] [be] essential | 5 |
|
| 7 | shown to [be] essential | 5 |
|
| 8 | show to [be] essential | 5 |
|
| 9 | shown to [be] essential | 5 |
|
