Yesterday, Miss Gao went to the street to buy walnuts. Unexpectedly, she was tricked: she spent ten dollars to buy back the inedible iron walnut. Miss Gao reminds everyone to pay more attention to buying walnuts on the roadside.

Miss Gao likes to eat walnuts. Yesterday morning, she rode past the provincial hospital and met a man pushing a bicycle to sell walnuts. She stopped to bargain, that is, she bought a catty of walnuts for ten dollars. When she got home, she took out walnuts to eat. But no matter how hard she knocks, the walnut is as hard as a stone and can't be knocked open. Finally, she had to use a dumbbell to crack the walnut. When I opened it, it was just a piece of dried meat, which was black and could not be eaten at all. After that, she opened several more in succession, all of which were like this. At this point, she knew that the vendor had used a cover-up, and she was cheated.

It turned out that the walnut she bought was called iron walnut, which was specially used to squeeze iron walnut oil and could not be eaten at all. It is understood that there is generally a black plastic bag next to the bamboo basket where these vendors put walnuts, which is filled with thin-skinned walnuts. During the "demonstration", the vendors took out the plastic bags, and the "iron walnuts" in the basket were sold exclusively to the public. The walnut in the plastic bag looks no different from that in the basket on the surface, but the weight in the hand is obviously different. Someone once did an experiment, weighing 28 "iron walnuts" with a scale, but weighing 54 "thin-skinned" walnuts. Thin-skinned walnuts are fragile and full of nuts. The "iron walnut" is not only "resistant to smashing", but also a few walnuts inside can't be picked out at all.