题目

_______ Tom, we wouldn’t have been late for the last bus. A. If we didn’t wait for               B. If we haven’t waited for C. we hadn’t waited for               D. Had we not waited for 答案：D 解析: 略现有24%的硝酸钾溶液、2%的硝酸钾溶液、硝酸钾固体和水．请选用上述不同物质配制10%的硝酸钾溶液，将用量的最简整数比填入下表中相应的位置．