know one’s cans懂行

【使用地区】：美国西部

【释义】：

Cowboys on the range in the nineteenth century were usually starved for reading matter and often read the labels on the cook’s tin cans，learning them by heart．A tenderfoot could always be distinguished because hedidn’t know his cans．

19世纪牧场上的牛仔常常渴求文字读物，因而经常读一些食物罐头上的标签，并熟记在心。如果看不懂罐头上的标签(意为“不懂行”)，就可知道此人必定是新来者。所以新手总是很容易识别。