◎ 题干

These rivers should be prevented ___________.
A.to be polluted B.from being polluted C.polluting D.being polluted
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◎ 解析
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◎ 知识点
    根据魔方格专家分析,试题“These rivers should be prevented ___________.A.to be pollutedB.from being pollutedC.pollutingD.being polluted…”主要考查了你对  【独立主格结构】  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。