题目

—“Don’t ____ to strangers on your way to and from school.” Mother often ____to me A. speak, says       B. speak , tells        C. talk, speaks       D. talk, tells 答案：A在下列物质（A）：烧碱，（B）NH3．H2O，（C）SO3，（D）铁片，（E）食盐水，（F）甲烷，（G）醋酸，（H）碳酸钙中，属于电解质的是ABGHABGH，属于非电解质的是CFCF，既不属于电解质又不属于非电解质DEDE．