| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [am/are] at [art] | 820 |
|
| 2 | operating at [art] | 39 |
|
| 3 | [am/are] operating at | 16 |
|
| 4 | [am/are] operating [art] | 8 |
|
