| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [noun] must be left [prep] | 15 |
|
| 2 | must [not/n't] be left [prep] | 9 |
|
| 3 | [noun] must [not/n't] be [prep] | 8 |
|
| 4 | [noun] must [not/n't] be left | 8 |
|
