| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | must be [vb pp] at [art] [noun sg] | 53 |
|
| 2 | must be [vb pp] at the [noun sg] | 47 |
|
| 3 | must be [vb pp] at [art] outset | 13 |
|
| 4 | must be [vb pp] at [art] time | 11 |
|
| 5 | must be [vb pp] at [art] end | 6 |
|
| 6 | must be made at [art] [noun sg] | 5 |
|
