diff --git a/w6/1 b/w6/1
new file mode 100644
index 0000000..10202e1
--- /dev/null
+++ b/w6/1
@@ -0,0 +1,3 @@
+public abstract class Animal {
+    public abstract void makeSound ();
+}
\ No newline at end of file
diff --git a/w6/2 b/w6/2
new file mode 100644
index 0000000..9fe80ab
--- /dev/null
+++ b/w6/2
@@ -0,0 +1,6 @@
+public class Cat extends Animal{
+    @Override
+    public void makeSound() {
+        System.out.println("猫：喵喵喵");
+    }
+}
\ No newline at end of file
diff --git a/w6/3 b/w6/3
new file mode 100644
index 0000000..af8b7b6
--- /dev/null
+++ b/w6/3
@@ -0,0 +1,11 @@
+public class Dog extends Animal implements Swimmable{
+    @Override
+    public void makeSound() {
+        System.out.println("狗：汪汪汪");
+    }
+
+    @Override
+    public void swim() {
+        System.out.println("狗会游泳");
+    }
+}
\ No newline at end of file
diff --git a/w6/4 b/w6/4
new file mode 100644
index 0000000..ad7f4a0
--- /dev/null
+++ b/w6/4
@@ -0,0 +1,20 @@
+public class Main {
+    public static void main(String[] args){
+        Animal dog = new Dog();
+        Animal cat = new Cat();
+
+        System.out.println("动物叫声");
+        dog.makeSound();
+        cat.makeSound();
+
+        System.out.println("是否会游泳");
+        if (dog instanceof Swimmable){
+            ((Swimmable) dog).swim();
+        }
+        if (cat instanceof Swimmable){
+            ((Swimmable) cat).swim();
+        } else {
+            System.out.println("猫不会游泳");
+        }
+    }
+}
\ No newline at end of file
diff --git a/w6/5 b/w6/5
new file mode 100644
index 0000000..26c5a27
--- /dev/null
+++ b/w6/5
@@ -0,0 +1,3 @@
+public interface Swimmable {
+    void swim();
+}
\ No newline at end of file