| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [adv] [verb] at the time | 225 |
|
| 2 | [adv] investigate at the [noun] | 7 |
|
| 3 | [adv] investigate at the time | 6 |
|
| 4 | [adv] investigate [prep] the time | 6 |
|
| 5 | [adv] investigate at [art] time | 6 |
|
| 6 | [adv] investigate [prep] the time | 6 |
|
