下列各组物质中,前者属于单质,后者属于混合物的是(    ) A.

下列各组物质中,前者属于单质,后者属于混合物的是(   

A.二氧化碳,食盐水        B.金刚石,净化后的空气

C.矿泉水,河水          D.臭氧,冰水混合物

答案

B

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