| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [vb mod] be observed that | 40 |
|
| 2 | [vb mod] [be] observed that | 40 |
|
| 3 | may [be] observed that | 16 |
|
| 4 | will [be] observed that | 12 |
|
| 5 | must [be] observed that | 9 |
|
