| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | they must be [prep] | 52 |
|
| 2 | they must be [prep] | 51 |
|
| 3 | they must be in | 18 |
|
| 4 | they must be of | 7 |
|
| 5 | they must be at | 6 |
|
| 6 | they must be on | 6 |
|
| 7 | they must be worth | 5 |
|
