| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [noun] required [prep] [det] a [noun sg] | 6 |
|
| 2 | be required [prep] [det] a [noun sg] | 5 |
|
| 3 | [be] required [prep] [det] a [noun sg] | 5 |
|
