| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | a attack on [art] police [noun sg] | 5 |
|
| 2 | a attack on [art] [noun pl] [noun sg] | 5 |
|
| 3 | a attack on a [noun pl] [noun sg] | 5 |
|
| 4 | an attack on [art] [noun pl] [noun sg] | 5 |
|
