托福閱讀長難句：美國商業(yè)廣播節(jié)目
Their competition and collaboration werecreating the broadcasting industry in the United States, beginning with theintroduction of commercial radio programming in the early 1920s.
記憶單詞：
competition n.比賽
competitor n.參賽者
competent adj.有能力的
competence n.能力
collaboration n.合作
collaborate v.合作
commercial adj.商業(yè)的
commodity n.商品
理解句子：
此句結構清晰，劃線部分為分詞作狀語。