题目

The decision has been made ________ the new school building be built next month. A．why                               B．how C．whether                           D．that 答案：D除去下列物质中的少量杂质，所选试剂及操作都正确的是（　　）选项物质杂质（少量）试剂操作方法ANaOH溶液Na2CO3过量的Ca（OH）2过滤BKC1MnO2适量的水加水溶解、过滤、洗涤、干燥CNaClNaOH适量的稀硫酸蒸发结晶DFeCl2溶液稀HCl过量铁粉过滤A. A B. B C. C D. D