| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | is [adv] [v-ing] on a | 46 |
|
| 2 | it is [adv] [v-ing] a | 34 |
|
| 3 | it is [adv] [v-ing] on | 17 |
|
| 4 | it is [v-ing] on a | 8 |
|
