| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [be] traced back [prep] | 107 |
|
| 2 | can [be] traced back | 99 |
|
| 3 | can [be] traced [prep] | 98 |
|
| 4 | can [be] back [prep] | 7 |
|
