Food serves as a form of communication in two fundamental ways. Sharing bread or other foods is a common human tradition that can promote unity and trust. Food can also have a specific meaning, and play a significant role in a family or culture's celebrations or traditions. The foods we eat--and when and how we eat them--are often unique to a particular culture or may even differ between rural   and urban areas within one country. Sharing bread, whether during a special occasion   or at the family dinner table, is a common symbol of togetherness. Many cultures also celebrate birthdays and marriages with cakes that are cut and shared among the guests. Early forms of cake were simply a kind of bread, so this tradition hits its roots in the custom of sharing bread. Food also plays an important role in many New Year celebrations. In the southern United States, pieces of corn bread represent blocks of gold for prosperity   in the New Year. In Greece, people share a special cake called vasilopita. A coin is put into the cake, which signifies   success in the New Year for the person who receives it. Many cultures have ceremonies to celebrate the birth of a child, and food can play a significant role. In China, when a baby is one month old, families name and welcome their child in a celebration that includes giving red-colored eggs to guests. In many cultures, round foods such as grapes, bread, and moon cakes are eaten at welcome celebrations to represent family unity. Nutrition is necessary for life, so it is not surprising that food is such an important part of different cultures around the world. The author explains the role of food in celebrations by  _  .
using examples making comparisons analyzing causes describing processes