Be careful with that knife. It's got a keen edge.

小心那把刀子，他有锐利的锋刃。

I must say, ever since you started having regular intercourse, your mind has lost its keen edge. You should reflect on that.

我不得不说 自从你开始定期交媾之后 你的脑子就没那么好使了 你应该采取点儿措施的。

Lizzie's professional honor had a keen edge, but she had been spared the vulgar necessity of making him feel it.

莉齐的职业荣誉有很强的优势， 但她没有让他感受到它的粗俗必要性。