knife straightedge

例句：

1. 1. She used a knife to cut the cake into pieces.
   她用刀把蛋糕切成了块。
2. 2. The chef used knives to chop vegetables for the salad.
   厨师用刀切蔬菜做沙拉。
3. 3. Knives are essential tools for cooking and cutting meat.
   刀是烹饪和切割肉类的必备工具。