题目

把NaHCO3和Na2CO3·10H2O混合物6.56g溶于水制成100mL溶液，测得溶液中Na＋的浓度为0.5mol/L。向该溶液中加入一定量盐酸恰好完全反应，将溶液蒸干后，所得固体质量为（） A . 2.925g B . 5.85 g C . 6.56g D . 无法确定 答案：A –I didn’t invite him to the party but he came anyway and got completely drunk.   --__________he hadn’t come! The party could have been a success. A. How come        B. Only if            C. What if          D. If only