| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | of [noun sg] [noun] [prep] | 16902 |
|
| 2 | levels of [noun] [prep] | 571 |
|
| 3 | levels of [noun sg] [prep] | 513 |
|
| 4 | levels of [noun sg] [noun] | 396 |
|
