| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb -s] be going on at | 7 |
|
| 2 | [vb -s] be [v-ing] on at | 7 |
|
| 3 | [vb -s] been [v-ing] on at | 7 |
|
| 4 | has be [v-ing] on at | 6 |
|
