Their competition and collaboration werecreating the broadcasting industry in the United States, beginning with theintroduction of commercial radio programming in the early 1920s.

　　记忆单词：

　　competition n.比赛

　　competitor n.参赛者

　　competent adj.有能力的

　　competence n.能力

　　collaboration n.合作

　　collaborate v.合作

　　commercial adj.商业的

　　commodity n.商品

　　理解句子：

　　此句结构清晰，划线部分为分词作状语。