| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | levels of [noun] [noun] [prep] | 74 |
|
| 2 | levels of [noun sg] [noun] [prep] | 66 |
|
| 3 | levels of [noun] [noun sg] [prep] | 64 |
|
| 4 | levels of [noun] [noun] in | 32 |
|
| 5 | levels of [noun] [noun] in | 32 |
|
| 6 | levels of [noun] [noun pl] [prep] | 10 |
|
| 7 | levels of [noun] [noun] for | 8 |
|
| 8 | levels of [noun] [noun] for | 8 |
|
| 9 | levels of [noun] dioxide [prep] | 7 |
|
| 10 | levels of [noun] dioxide [prep] | 7 |
|
| 11 | levels of [noun] [noun] at | 5 |
|
| 12 | levels of [noun] [noun] at | 5 |
|
