| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | it be [adv] [adj] maintain | 22 |
|
| 2 | it be [adv] [adj] maintain | 21 |
|
| 3 | it be [adv] difficult maintain | 7 |
|
| 4 | it be [adv] difficult maintain | 7 |
|
