| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [prep] a million years | 41 |
|
| 2 | [prep] a million years | 41 |
|
| 3 | in a million years | 28 |
|
| 4 | in a million years | 28 |
|
| 5 | for a million years | 6 |
|
| 6 | for a million years | 6 |
|
