| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | must [be] [v-ing] in [pos pn] [noun sg] | 6 |
|
| 2 | must [be] [v-ing] in [pron] [noun sg] | 6 |
|
| 3 | must [be] [v-ing] in [art] [noun sg] | 5 |
|
| 4 | must [be] [v-ing] in [art] [noun sg] | 5 |
|
