| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] [noun sg] have [been] concerned | 6 |
|
| 2 | [prep] [noun sg] have [been] concerned | 6 |
|
| 3 | [prep] [noun sg] have been concerned | 6 |
|
| 4 | [prep] [noun sg] has [been] concerned | 5 |
|
