| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | they must be [prep] [noun] | 8 |
|
| 2 | they must be [prep] [noun] | 8 |
|
| 3 | they must be [prep] [noun] | 8 |
|
| 4 | they must be [prep] [noun sg] | 6 |
|
| 5 | they must be in [noun] | 5 |
|
| 6 | they must be in [noun] | 5 |
|
