In fact, a duck does have only one duck tongue, but there are quite a few duck tongues on the market, mainly because duck tongues are very popular in deli, so there is a great demand. In order to expand the sales of duck tongue, merchants use consumers' psychology to drive up the price of duck tongue, claiming that "duck tongue is the healthiest part of duck body" to attract consumers to buy it. However, this statement is more of a marketing tool for businesses. Although duck tongue is a part of duck, it naturally contains some nutrients of duck meat, but it is difficult to ensure the nutritional value of duck tongue in the subsequent production process because duck tongue can only be eaten after cleaning, and many unscrupulous traders in the market will soak duck tongue with something to save trouble. The soaked duck tongue will be cleaned immediately after it is taken out, and then pickled into duck tongue that we eat in our stomachs. Soaking duck tongue with strong alkali water is harmful to human body and will corrode esophageal and gastric mucosa.