| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | go back [prep] the [adj] century | 6 |
|
| 2 | go back to [art] [adj] century | 6 |
|
| 3 | go back [prep] [art] [adj] century | 6 |
|
| 4 | go back [prep] [art] [num ord] century | 6 |
|
