| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | have been [v-ing] [prep] a | 521 |
|
| 2 | which have been [v-ing] [prep] | 128 |
|
| 3 | which have been [prep] a | 14 |
|
| 4 | which have been [v-ing] a | 12 |
|
