| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | be introduced in the [num ord] [noun sg] | 13 |
|
| 2 | be introduce in the [num ord] century | 7 |
|
| 3 | was introduce in the [num ord] [noun sg] | 6 |
|
| 4 | were introduce in the [num ord] [noun sg] | 5 |
|
