| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [noun prp] [noun prp] must be [verb] | 47 |
|
| 2 | [noun prp] [noun prp] must be [vb pp] | 34 |
|
| 3 | [noun prp] [noun prp] must be [v-ing] | 13 |
|
