| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] which we must [vb infin] | 18 |
|
| 2 | [prep] which we must [vb infin] | 18 |
|
| 3 | to which we must [vb infin] | 5 |
|
| 4 | in which we must [vb infin] | 5 |
|
