| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it has been [v-ing] | 132 |
|
| 2 | it has been working | 11 |
|
| 3 | it has been going | 8 |
|
| 4 | it has been developing | 5 |
|
| 5 | it has been operating | 5 |
|
