| 1 | His voice is very flat, sounding completely unexcited. | |
| 2 | The terrain in this region is flat and suitable for agricultural development. | |
| 3 | The terrain of this place is very flat, suitable for constructing farmland. | |
| 4 | The road surface is indeed flat, and it is very comfortable to ride a bicycle. | |
| 5 | The tone of this musical instrument is very flat, with not much variation. |
