◎ 题干
Many rivers ________.
[     ]
A. have became polluted
B. have become polluted
C. have been polluting
D. have become polluting
◎ 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“Many rivers ________. [ ]A. have became polluted B. have become polluted C. have been polluting D. have become polluting …”主要考查了你对  【实义动词】【分词】  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。