| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | at an [adj] [noun sg] | 2058 |
|
| 2 | introduced at [adj] [noun sg] | 15 |
|
| 3 | introduced an [adj] [noun sg] | 14 |
|
| 4 | introduced at an [adj] | 6 |
|
