diff --git a/W6/Animal.java b/W6/Animal.java
new file mode 100644
index 0000000..35afd60
--- /dev/null
+++ b/W6/Animal.java
@@ -0,0 +1,26 @@
+abstract class Animal {
+    public abstract void makeSound();
+}
+
+interface Swimmable {
+    void swim();
+}
+
+class Dog extends Animal implements Swimmable {
+    @Override
+    public void makeSound() {
+        System.out.println("汪汪汪！");
+    }
+
+    @Override
+    public void swim() {
+        System.out.println("小狗在水里游泳！");
+    }
+}
+
+class Cat extends Animal {
+    @Override
+    public void makeSound() {
+        System.out.println("喵喵喵！");
+    }
+}