| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | be used [prep] [det] [noun] | 260 |
|
| 2 | should be used [prep] [noun] | 50 |
|
| 3 | should be [prep] [det] [noun] | 30 |
|
| 4 | should be used [prep] [det] | 29 |
|
