| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [verb] at [art] level | 213 |
|
| 2 | operate at [art] [noun] | 59 |
|
| 3 | operate at [art] [noun sg] | 54 |
|
| 4 | operate [prep] [art] level | 14 |
|
| 5 | operate at [art] level | 9 |
|
