Found in nature？ yes No Not concocted？ Yes No Recognized by the body？ YesCaCO3 No Not harmful？ Yes No Do we define it as food？ No Yes Does it taste good？ We don’t know Yes According to this form, we can found cockroaches are more accord with the definition of what we think food should be.Actually, this form is based on how people defined food, and we can give an adverse example. We defined food by our culture, and the norm is what we know. So if you were burning in tropic, you might like eat cockroaches. 2. Advertisement influence our choice I know for almost all cultures hamburgers are food. Why people believe it like truth? Of course, we know hamburgers can be eaten, but for people who are live in the culture which like eat cockroaches, hamburgers still are food.In other word, something has told us that hamburgers were food. What it is? Perhaps not culture because hamburgers didn’t belong to any original culture. From the paper History and Legends of Hamburgerswe can realize that the beginning of hamburgers was 15th century, but you may never see any classical book, I mean the book which published 100 years ago, mentioned hamburgers. Suddenly hamburgers become the most popular food in America, and third world countries. In this paper, author mentioned “The hamburger gets its first widespread attention at the 1904 World's Fair in St. Louis, Missouri, also known as the Louisiana Purchase Exhibition, where it created a sensation. A reporter for the New York Tribune wrote from the 1904 St. Louis World's Fair of a new sandwich called a hamburger, “the innovation of a food vendor on the pike.” By “Pike” he meant the World's Fair midway.” World's Fair is a good advertisement in the day no televisions, even now people still crazy for different exhibitions. For instance, women would like to hear the word --Paris Fashion Week. Hamburgers are a symbol of junk food, but we cannot stop eat it even if we know is junk food. Why does this happen? From the research ofEating More; Enjoying Less By Pew Social Trends Staff we can see this form. In this research paper, we can find advertisement is a big deal to influence our social life. “Both groups agree that convenience is the biggest reason for America’s junk food habit. But among those who say they rarely or never overeat junk food, there is a greater tendency to stress the importance of advertising as a factor in the consumption of junk food by others.” 3. How society, for example the government, influenced our choice？ People in third world might believe coca-cola is better than their water. That is a big problem because it may lead people to a wrong way of understanding food. The health minister of china says that nutrition is a bigger problem than under nutrition. Scenes like this are becoming more