Customs play a significant role in festivals but sometimes they can change over timeWith the development of modern society and the spread of new ideas some traditions may fade away and others may be e

Customs play a significant role in festivals, but sometimes they can change over time.

这句话中的知识点是“主语+谓语”结构。主语是“Customs”，谓语是“play a significant role”。

With the development of modern society and the spread of new ideas, some traditions may fade away and others may be established.

这句话中的知识点是“with+名词短语”结构和“may+动词不定式”结构。其中，“with the development of modern society and the spread of new ideas”是一个介词短语，作为句子的状语；“some traditions may fade away and others may be established”是一个主语“some traditions”和谓语“may fade away and be established”的句子结构。

One example is the typical Chinese Spring Festival custom of lighting firecrackers to drive away the evil spirits and celebrate the new year.

这句话中的知识点是“one example is”和“to+动词不定式”结构。其中，“one example is”是一个主语“one example”和谓语“is”的句子结构；“to drive away the evil spirits and celebrate the new year”是一个不定式短语，修饰前面的名词“custom”。

Nowadays, many big cities have given up this custom in order to avoid air pollution.

这句话中的知识点是“in order to+不定式”结构。这个结构表示目的。其中，“in order to avoid air pollution”是一个状语，修饰前面的动词短语“have given up this custom”。

Another example is Halloween, which slowly became an exciting festival for children, in spite of its religious origins.

这句话中的知识点是“which+从句”结构和“in spite of+名词短语”结构。其中，“which slowly became an exciting festival for children”是一个非限制性定语从句，修饰前面的名词“Halloween”；“in spite of its religious origins”是一个介词短语，表示尽管有宗教起源