| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | be [verb] while [v-ing] at [art] | 6 |
|
| 2 | [be] [verb] while [v-ing] at [art] | 6 |
|
| 3 | [verb] while [v-ing] at [art] [noun sg] | 6 |
|
| 4 | [verb] while [v-ing] at [art] [noun] | 6 |
|
