| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [v-ing] [conj] it must [verb] [be] | 6 |
|
| 2 | [v-ing] [conj] it must have [be] | 6 |
|
| 3 | [v-ing] [conj] it must have [be] | 6 |
|
| 4 | [v-ing] [conj] it must [vb infin] [be] | 6 |
|
