A:母鸡下蛋
B:猫捉老鼠
C:胃的蠕动
D:兔子竖起耳朵
某碳酸钠样品中混有少量氯化钠,根据如图所示信息完成相关计算。
(反应的化学方程式为:CaCl2+Na2CO3=CaCO3↓+2NaCl)
— I don't know .— Because he has to look after his mother.