| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [noun] is [v-ing] the system | 6 |
|
| 2 | [noun sg] is [v-ing] the system | 5 |
|
| 3 | is [v-ing] [prep] the system | 5 |
|
| 4 | is [v-ing] [prep] the system | 5 |
|
