| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a [noun pl] ' | 413 |
|
| 2 | at [art] [noun pl] ' | 257 |
|
| 3 | at a [noun pl] [unc] | 60 |
|
| 4 | at a [noun] ' | 45 |
|
