题目

 The pop star walked out of the stage, ______ her hands elegantly to her crazy fans.   A. waving             B. was waving             C. waved                     D. to wave 答案：A C和CaCO3的混合物在空气中加强热后，CaCO3完全分解，C被完全氧化，若生成物中CO2的质量与原混合物的质量相等，则原混合物中C的质量分数为________．