What are the characteristics of cross talk?

Crosstalk is a folk art, which makes the audience laugh by telling jokes or interesting questions and answers. It evolved from "Xiang Sheng" in the Song Dynasty. In the later period of Beijing School, crosstalk formed modern characteristics and styles. Mainly in Beijing dialect, there are also "dialect crosstalk" in local dialects. "Speaking, learning, teasing and singing" are the basic artistic means of cross talk tradition. "Speaking" refers to telling jokes and tongue twisters, "learning" refers to imitating all kinds of hawking, chirping of birds and animals, singing of dramas and styles and languages of various characters, and "teasing" refers to making up some funny words, singing them in various tunes, or exaggerating some lyrics and tunes of operas to make people laugh.