◎ 题干
Sales of CDs have greatly increased since the early 1990s, when people _______to enjoy the advantages of this new technology.

A. begin
B. began
C. have begun
D. had begun
◎ 答案
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◎ 解析
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◎ 知识点
    根据n多题专家分析,试题“Sales of CDs have greatly increased since the early 1990s, when people _____ to enjoy the advantages of this new technology. [ ]A. begin B. began C. have beg…”主要考查了你对  【一般过去时】  等知识点的理解和应用能力。关于这些知识点的“档案”,你可以点击相应的链接进行查看和学习。