赋值为什么没生效

class AA{
String name;
int   age;
public AA(){}
public String talk()
{
return("姓名:"+name+"\n年龄："+age);
}
}

class BB  extends AA{
String school;
public  BB(String name,int age,String School)
{
super.name=name;
super.age=age;
System.out.println(super.talk());
this.school=school;//赋值没有生效}

}

public class TestSuper {
    public static void main(String[] args) {
// TODO 自动生成的方法存根
   BB   b1=new BB("张三",20,"北大");
   System.out.println("学校:"+b1.school);
}

}

Java 构造函数
[解决办法]
String School
this.school=school; 这么明显就不需要解释了吧
[解决办法]
楼上正确..