| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | a level of [noun sg] [prep] | 38 |
|
| 2 | a level of [noun] of | 7 |
|
| 3 | a level of [noun] in | 7 |
|
| 4 | a level of [noun] for | 5 |
|
