| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | should [vb infin] and [vb infin] [prep] [art] | 12 |
|
| 2 | should [vb infin] and [vb infin] [prep] a | 7 |
|
| 3 | should [vb infin] and [vb infin] [prep] the | 5 |
|
