| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | is [verb] the [adj] system | 12 |
|
| 2 | be [to-vb] the [adj] system | 9 |
|
| 3 | be [v-ing] the [adj] system | 9 |
|
| 4 | was [verb] the [adj] system | 5 |
|
