flat terrain

例句：

1. 1. The road is very flat and easy to drive on.
   这条路非常平坦，易于驾驶。
2. 2. The table is flat, so it's easy to clean.
   桌子是平的，所以很容易清洁。
3. 3. The ground was flat and covered in grass.
   地面平坦，覆盖着草。