Be careful when you enemy invites you.
农夫和蛇
The Farmer and the Snake
有个农夫在冬天发现一条被冻僵了的蛇。善良的他非常可怜蛇，便把他放在自己怀里。感受到农夫身体的温暖后，蛇苏醒过来了，随即恢复了本性，狠狠地咬了他的恩人一口，足以致命。农夫明白自己的处境，不禁悲叹：“这就是我怜悯恶人的报应啊！”
邪恶本性是不会改变的。
One winter a Farmer found a Snake stiff and frozen with cold. He had compassion on it，and taking it up，placed it in his bosom. The Snake was quickly revived by the warmth，and resuming its natural instincts，bit its benefactor，inflicting on him a mortal wound. “Oh，”cried the Farmer with his last breath，“I am rightly served for pitying a scoundrel.”