sharp sand

例句：

1. 1. The knife is very sharp.
   这把刀非常锋利。
2. 2. The sharp edge of the knife cuts through anything.
   这把刀锋利的边缘能切穿任何东西。
3. 3. She sharpened her knives before going on a camping trip.
   她在去露营旅行前磨利了她的刀。