题目

It was graduation day at the university where I work and a beautiful day quite unlike the first graduation I attended as a young professor．On that cold day years ago, as we watched the students walking into the hall, one of my colleagues turned to me and said, Graduation will be one of the happiest and one of the saddest time of your life． At my inquiry, he answered, Because the students you have gotten to know have to leave． As years went by, my previous confusion about my colleague's words no longer existed．When I came across naughty students, I have had to rethink why I chose某同学利用括号内的物质设计的下列各实验方案中，你认为可行的是（　　）A．分离氯化钾中混有的氯酸钾粉末（加水溶解，过滤，蒸发）B．鉴别固体：氢氧化钠、氯化钠、硝酸铵（水）C．除去二氧化碳中混有少量的一氧化碳（点燃）D．验证铁、铜、银的金属活动性顺序（铜丝、硝酸银溶液、硝酸亚铁溶液）