| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | need to be kept [prep] | 32 |
|
| 2 | to be kept [prep] [adj] | 24 |
|
| 3 | need to be [prep] [adj] | 21 |
|
| 4 | need to be kept [adj] | 11 |
|
