题目

Linda Evans was my best friend—like the sister I never had. We did everything together：piano lessons，movies，swimming，horseback riding. When I was 13，my family moved away. Linda and I kept in touch through letters，and we saw each other on special times—like my wedding(婚礼) and Linda’s. Soon we were busy with children and moving to new homes，and we wrote less often. One day a card that I sent came back，stamped “Address(地址) Unknown” I had no idea how to find Linda. Over the years，I missed Linda very much. I wanted to share(分享) happiness of my children and th下列物质的分类标准正确的是（  ）。A．强碱和弱碱：电离出的OH－数目B．强电解质和弱电解质：溶液的导电能力强弱C．浊液、胶体、溶液：分散剂粒子直径大小D．氧化剂、还原剂：在化学反应中元素的化合价变化