弹簧刀

例句：

1. 1. This spring knife is very sharp and easy to use.
   这把弹簧刀很锋利，使用起来很方便。
2. 2. The hunter used a spring knife to cut through the thick brush.
   猎人用弹簧刀割断了浓密的灌木丛。
3. 3. The spring knife was a useful tool for survival in the wilderness.
   弹簧刀是野外生存中一个有用的工具。