| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | are required to [be] [vb pp] [prep] | 15 |
|
| 2 | are required to be [vb pp] [prep] | 15 |
|
| 3 | are required to be [vb pp] [prep] | 15 |
|
| 4 | are required to [be] [vb pp] [prep] | 15 |
|
