| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [pron] is [adv] [adj] maintain | 16 |
|
| 2 | [pron] is [adv] [adj] maintain | 15 |
|
| 3 | [pron] is [adv] difficult maintain | 6 |
|
| 4 | [pron] is [adv] difficult maintain | 6 |
|
