| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | once [vb past] [prep] [noun] | 92 |
|
| 2 | at once [prep] [noun] | 58 |
|
| 3 | at once [vb past] [prep] | 16 |
|
| 4 | at once [vb past] [noun] | 7 |
|
