superhard

例句：

1. 1.The rock is superhard and cannot be scratched with a knife.
   这块石头超级硬，用刀都刮不动。
2. 2.The car's tires are superhard, so it can handle rough terrain.
   这辆车的轮胎超级硬，所以能应对崎岖的地形。
3. 3. The material is superhard, making it ideal for cutting through thick materials.
   这种材料超级硬，非常适合切割厚重的材料。