题目

除去下列物质中的少量杂质所选用的试剂或方法正确的是（      ） 选项物质所含杂质所选用试剂或方法 ANaOH溶液Na2CO3 溶液稀盐酸 BCaOCaCO3高温灼烧 CCO2CO点燃 D稀盐酸稀硫酸加适量Ba(NO3)2溶液，再过滤 答案：B After       in the new course reform for many years, the English teacher published over 30 books.A．buried B．being buried C．having buriedD．having been buried