| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | which had [been] [v-ing] [prep] [num] | 8 |
|
| 2 | which had [been] [v-ing] [prep] [num] | 8 |
|
| 3 | which had been [v-ing] [prep] [num] | 8 |
|
