| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | be introduced in the [num ord] [noun sg] | 13 |
|
| 2 | be introduced [prep] the first [noun sg] | 11 |
|
| 3 | was introduced [prep] the [num ord] [noun sg] | 11 |
|
| 4 | be introduced [prep] the [num ord] century | 8 |
|
| 5 | were introduced [prep] the [num ord] [noun sg] | 7 |
|
| 6 | be introduced for the [num ord] [noun sg] | 6 |
|
| 7 | be introduced [prep] the [num ord] time | 6 |
|
