public class Father {

    public String name;

    public String bloodType;

    private int age;

    public void work() {

        System.out.println("working....");

    }

}

public class Son extends Father{

    public static void main(String[] args) {

        Father father = new Father();

        Son son = new Son();

        son.work();

        son.name = "son";

        System.out.println(son.name);

        //son.aget = 15;  不可以使用父类私有属性的成员变量和方法

    }

}

working....

son