| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | which must [verb] | 355 |
|
| 2 | which must [vb infin] | 354 |
|
| 3 | which [modal v] contain | 51 |
|
| 4 | [pron] must contain | 23 |
|
| 5 | which must contain | 6 |
|
