| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it must [be] observed that | 9 |
|
| 2 | [pron] must [be] observed that | 9 |
|
| 3 | [pers pn] must [be] observed that | 9 |
|
| 4 | it must [be] observed that | 9 |
|
