原式=2-1-8÷13=2-1-24=-23．故答案为-23．
The fans gave a(n) ________ description of the first match of the World Cup as if they were footballers.[ ]
A. creative
B. fantastic
C. imaginative
D. vivid
向20 mL 0.20 mol/L的NaOH溶液中，缓缓通入一定量的CO2气体，将溶液在一定条件下小心地蒸干，若得到白色固体为纯净物，则通入CO2的体积为________(标准状况)．写出反应的离子方程式：___________．
将上述白色固体加水溶解，加盐酸至中性，再蒸干得白色固体，质量为________g．
