| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | be required [to-vb] at | 22 |
|
| 2 | [be] required [to-vb] at | 22 |
|
| 3 | [be] required [to-vb] at | 12 |
|
| 4 | be required [to-vb] at | 12 |
|
| 5 | required [to-vb] [noun] at | 8 |
|
| 6 | required [to-vb] [adv] at | 5 |
|
| 7 | required [to-vb] at [adv] | 10 |
|
| 8 | required [to-vb] at [adj] | 9 |
|
| 9 | required [to-vb] at least | 9 |
|
| 10 | required [to-vb] at least | 9 |
|
| 11 | required [to-vb] at [adv] | 9 |
|
| 12 | required [to-vb] at [art] | 6 |
|
| 13 | required [to-vb] at [art] | 6 |
|
