| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | have [vb pp] [noun] to ensure | 10 |
|
| 2 | have [verb] [noun pl] to ensure | 7 |
|
| 3 | have take [noun] to ensure | 5 |
|
| 4 | have taken [noun] to ensure | 5 |
|
| 5 | have [verb] [noun] to ensure | 5 |
|
