| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it [is] [verb] at | 310 |
|
| 2 | [is] [verb] at [v-ing] | 135 |
|
| 3 | it [is] [verb] [v-ing] | 68 |
|
| 4 | it [verb] at [v-ing] | 12 |
|
| 5 | it [is] at [v-ing] | 5 |
|
