| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | have [been] in operation [prep] [adj] | 27 |
|
| 2 | have been in operation [prep] [adj] | 27 |
|
| 3 | have [been] in operation [prep] [num] | 18 |
|
| 4 | have [been] in operation for [adj] | 16 |
|
| 5 | has [been] in operation [prep] [adj] | 15 |
|
| 6 | had [been] in operation [prep] [adj] | 11 |
|
| 7 | have [been] in operation since [adj] | 9 |
|
| 8 | have [been] in operation [prep] [det] | 8 |
|
| 9 | have [been] in operation [prep] some | 5 |
|
| 10 | have [been] in operation [prep] some | 5 |
|
