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题文

在我们的日常生活中出现了“加碘食盐”、“增铁酱油”、“高钙牛奶”、“富硒茶叶”、“含氟牙膏”等商品。这里的碘、铁、钙、硒、氟应理解为                  

A.元素 B.单质 C.分子 D.氧化物
科目 化学   题型 选择题   难度 未知
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