| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [modal v] be back [prep] the | 123 |
|
| 2 | [modal v] be trace back [prep] | 91 |
|
| 3 | be trace back [prep] the | 50 |
|
| 4 | [modal v] be trace [prep] the | 48 |
|
