Look not for musk in dog's kennel.
---------------------------------------- A dog's mouth emits no ivory
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1.What can you expect from a dog but a bark.
2.A filthy mouth can't utter decent language.
有什么好话，讲出什么公理来，狗口里吐不出象牙。”
【出处】:元·高文秀《遇上皇》第一折：“和这等东西， 【解释】: 比喻坏人嘴里说不出好话来。