| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | have been used for [det] [noun pl] | 14 |
|
| 2 | have been used for many [noun pl] | 13 |
|
| 3 | have been used for [det] years | 12 |
|
| 4 | has been used for [det] [noun pl] | 8 |
|
