鉴别NaCl、NaBr、NaI可以选用的试剂是( ) A.碘水、淀粉溶液 B.氯水、四氯化碳C.溴水、汽油 D.硝酸银溶液、稀硝酸 答案:解析:Br2水能将NaI分出来,但不能区分NaCl、NaBr。Cl2水氧化NaBr,NaI2加CCl4后溶液颜色分别为橙红和紫红,用AgNO3分别生成AgCl、AgBr、AgI依次为白、淡黄、黄色。答案:BD---- _____ ?
---- I am 1.7 metres tall.
A. How old are you B. How
tall are you C. How big are you D. How are you