diff --git a/s-day02/src/com/inmind/generic_tpf08/Demo10.java b/s-day02/src/com/inmind/generic_tpf08/Demo10.java
index be20716..115f24f 100644
--- a/s-day02/src/com/inmind/generic_tpf08/Demo10.java
+++ b/s-day02/src/com/inmind/generic_tpf08/Demo10.java
@@ -5,6 +5,12 @@ import java.util.ArrayList;
 /*
 13.泛型通配符的使用(了解) ?
 当我们要接受一个数据类型，它的泛型不一致，要使用泛型通配符，匹配？
+
+----------------------------------------
+
+格式:
+    <? extends B> :泛型的类型只能是B类型或者B类型的子类；上限
+    <? super B> :  泛型的类型只能是B类型或者B类型的父类；下限
  */
 public class Demo10 {
     public static void main(String[] args) {
@@ -25,9 +31,21 @@ public class Demo10 {
     /*
         ArrayList<Object> 这样写的话是错的，泛型是没有多态的
      */
-    public static void showList(ArrayList<?> list){
+//    public static void showList(ArrayList<?> list){
+    //受限泛型的上限
+    public static void showList(ArrayList<? extends Person> list){
+        for (Person p : list) {
+            System.out.println(p);
+            p.show();
+            p.method();
+        }
+    }
+
+
+    //受限泛型的下限
+    /*public static void showList(ArrayList<? super Student> list){
         for (Object o : list) {
             System.out.println(o);
         }
-    }
+    }*/
 }
diff --git a/s-day02/src/com/inmind/generic_tpf08/Person.java b/s-day02/src/com/inmind/generic_tpf08/Person.java
index 2dab766..ef48f71 100644
--- a/s-day02/src/com/inmind/generic_tpf08/Person.java
+++ b/s-day02/src/com/inmind/generic_tpf08/Person.java
@@ -19,4 +19,12 @@ public class Person {
                 ", age=" + age +
                 '}';
     }
+
+    public void show(){
+        System.out.println("人类型可以调用的方法");
+    }
+
+    public void method(){
+        System.out.println("父类非私有功能");
+    }
 }
diff --git a/s-day02/src/com/inmind/generic_tpf08/Student.java b/s-day02/src/com/inmind/generic_tpf08/Student.java
index daf605e..9f224d9 100644
--- a/s-day02/src/com/inmind/generic_tpf08/Student.java
+++ b/s-day02/src/com/inmind/generic_tpf08/Student.java
@@ -16,4 +16,14 @@ public class Student extends Person{
                 ", name='" + name + '\'' +
                 '}';
     }
+
+    @Override
+    public void show() {
+        System.out.println("学生重写show");
+    }
+
+    @Override
+    public void method() {
+        System.out.println("学生重写method");
+    }
 }