| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adj] system had [prep] be | 5 |
|
| 2 | [adj] system had [prep] be | 5 |
|
| 3 | system had [prep] be [vb pp] | 9 |
|
| 4 | system had [prep] be [verb] | 9 |
|
