题目

   I hear many parents complaining that their teenage children are rebelling. I wish it were so. At your age you ought to be growing away from your parents. You should be learning how to stand on your own two feet. But take a look at the present rebellion. It seems that teenagers are all taking the same way of showing that they disagree with their parents. Instead of striking out boldly on their own, most of them are clutching at (attempting to seize) one another's hands for reassurance.      They claim that they want to dress as they please. But they all wear the same clothes. 3．物质的性质决定其用途，下列说法错误的是（　　）A．石墨具有导电性，常用作电极B．氧化钙能与水反应，可用作干燥剂C．小苏打能与酸反应，可用于治疗胃酸过多D．氢氧化钠溶液显碱性，常用于改良酸性土壤