| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it must [adv] be | 328 |
|
| 2 | it [adv] be [prep] | 239 |
|
| 3 | it must be [prep] | 189 |
|
| 4 | must [adv] be [prep] | 118 |
|
