Customs play a significant role in festivals, but sometimes they can change over time. With the development of modern society and the spread of new ideas, some traditions may fade away and others may (establish). One example is the typical Chinese Spring Festival custom of (light) firecrackers to drive away the evil spirits and celebrate the new year. Nowadays, many big cities (give) up this custom in order to avoid air pollution. Another example is Halloween, which slowly became an (excite) festival for children, in spite of its religious origins.
