| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | be [vb pp] [adv prt] by | 1215 |
|
| 2 | must be [vb pp] by | 795 |
|
| 3 | must be [vb pp] [adv prt] | 381 |
|
| 4 | must be [adv prt] by | 16 |
|
