A:倒立缩小
B:倒立等大
C:倒立放大
D:正立放大
【制取MgCO3·3H2O】工业上从弱碱性卤水(主要成分为MgCl2)中获取MgCO3·3H2O的方法如下:
图1 获取MgCO3·3H2O的工艺流程
图2沉淀过程的pH变化 图3不同温度下溶液中镁离子含量随时间的变化
命题“∀x2>1,x>1” 的否定是( )
— Have you seen the film called The trouble with Teenagers?
—Yes, but I don't think it is worth _______.