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某溶液中加入硝酸银溶液生成白色沉淀 说明原溶液中有Cl-对吗?
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Are these their ____? A. child B. children C. a child
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When I was young, I was always frustrated ( 挫败的 ), and almost everything ended in failure.
1年前
100吨海水含盐三吨,照这样计算十吨100吨海水各含盐多少吨?
1年前
People are using more and more natural gas, wind and other forms of _____. [ ]
1年前