diff --git a/docs/坦克大战笔记.docx b/docs/坦克大战笔记.docx
index bd38f63..8435f34 100644
Binary files a/docs/坦克大战笔记.docx and b/docs/坦克大战笔记.docx differ
diff --git a/src/com/demo/tank/course3/Bullet.java b/src/com/demo/tank/course3/Bullet.java
index e3b46bf..f8de131 100644
--- a/src/com/demo/tank/course3/Bullet.java
+++ b/src/com/demo/tank/course3/Bullet.java
@@ -9,12 +9,14 @@ public class Bullet {
     public static final int WIDTH = ResourceManager.bulletD.getWidth();
     public static final int HEIGHT = ResourceManager.bulletD.getHeight();
     private boolean live = true;
+    private Group group = Group.BAD;
     private TankFrameV3 tf;
 
-    public Bullet(int x, int y, Direction direction, TankFrameV3 tf) {
+    public Bullet(int x, int y, Direction direction, Group group, TankFrameV3 tf) {
         this.x = x;
         this.y = y;
         this.direction = direction;
+        this.group = group;
         this.tf = tf;
     }
 
@@ -59,6 +61,8 @@ public class Bullet {
 
     //检测是否跟坦克碰撞
     public void collideWith(Tank tank){
+        //关闭队友伤害
+        if(this.group == tank.getGroup()) return;
         Rectangle bulletRect = new Rectangle(x, y, WIDTH, HEIGHT);
         Rectangle tankRect = new Rectangle(tank.getX(), tank.getY(), Tank.WIDTH, Tank.HEIGHT);
         if(bulletRect.intersects(tankRect)){
@@ -102,4 +106,12 @@ public class Bullet {
     public void setLive(boolean live) {
         this.live = live;
     }
+
+    public Group getGroup() {
+        return group;
+    }
+
+    public void setGroup(Group group) {
+        this.group = group;
+    }
 }
diff --git a/src/com/demo/tank/course3/Explode.java b/src/com/demo/tank/course3/Explode.java
new file mode 100644
index 0000000..af3c32f
--- /dev/null
+++ b/src/com/demo/tank/course3/Explode.java
@@ -0,0 +1,43 @@
+package com.demo.tank.course3;
+
+import java.awt.*;
+
+public class Explode {
+    private int x, y;
+    public static final int WIDTH = ResourceManager.explodes[0].getWidth();
+    public static final int HEIGHT = ResourceManager.explodes[0].getHeight();
+    private boolean living = true;
+    private TankFrameV3 tf;
+
+    private int step = 0;
+
+    public Explode(int x, int y, TankFrameV3 tf) {
+        this.x = x;
+        this.y = y;
+        this.tf = tf;
+    }
+
+    public void paint(Graphics g){
+        g.drawImage(ResourceManager.explodes[step++], x, y, null);
+        if(step >= ResourceManager.explodes.length){
+            step = 0;
+        }
+    }
+
+    public int getX() {
+        return x;
+    }
+
+    public void setX(int x) {
+        this.x = x;
+    }
+
+    public int getY() {
+        return y;
+    }
+
+    public void setY(int y) {
+        this.y = y;
+    }
+
+}
diff --git a/src/com/demo/tank/course3/Group.java b/src/com/demo/tank/course3/Group.java
new file mode 100644
index 0000000..e37c523
--- /dev/null
+++ b/src/com/demo/tank/course3/Group.java
@@ -0,0 +1,5 @@
+package com.demo.tank.course3;
+
+public enum Group {
+    GOOD, BAD
+}
diff --git a/src/com/demo/tank/course3/MainV3.java b/src/com/demo/tank/course3/MainV3.java
index ffd0a53..97edf45 100644
--- a/src/com/demo/tank/course3/MainV3.java
+++ b/src/com/demo/tank/course3/MainV3.java
@@ -6,7 +6,7 @@ public class MainV3 {
     public static void main(String[] args) throws InterruptedException, IOException {
         TankFrameV3 tf = new TankFrameV3();
         for(int i = 0; i < 5; i++){
-            tf.enemyTanks.add(new Tank(50 + i*80, 200, Direction.DOWN, tf));
+            tf.enemyTanks.add(new Tank(50 + i*80, 200, Direction.DOWN, Group.BAD, tf));
         }
 
         while (true){
diff --git a/src/com/demo/tank/course3/ResourceManager.java b/src/com/demo/tank/course3/ResourceManager.java
index e981221..288ef1a 100644
--- a/src/com/demo/tank/course3/ResourceManager.java
+++ b/src/com/demo/tank/course3/ResourceManager.java
@@ -7,6 +7,7 @@ import java.io.IOException;
 public class ResourceManager {
     public static BufferedImage tankL, tankR, tankU, tankD;
     public static BufferedImage bulletL, bulletR, bulletU, bulletD;
+    public static BufferedImage[] explodes = new BufferedImage[16];
 
     static {
         try {
@@ -19,6 +20,10 @@ public class ResourceManager {
             bulletR = ImageIO.read(ResourceManager.class.getClassLoader().getResourceAsStream("com/demo/tank/images/bulletR.gif"));
             bulletU = ImageIO.read(ResourceManager.class.getClassLoader().getResourceAsStream("com/demo/tank/images/bulletU.gif"));
             bulletD = ImageIO.read(ResourceManager.class.getClassLoader().getResourceAsStream("com/demo/tank/images/bulletD.gif"));
+
+            for (int i= 0; i<16; i++){
+                explodes[i] = ImageIO.read(ResourceManager.class.getClassLoader().getResourceAsStream("com/demo/tank/images/e"+ (i+1)+".gif"));
+            }
         } catch (IOException e) {
             e.printStackTrace();
         }
diff --git a/src/com/demo/tank/course3/Tank.java b/src/com/demo/tank/course3/Tank.java
index cd30222..b18d1ee 100644
--- a/src/com/demo/tank/course3/Tank.java
+++ b/src/com/demo/tank/course3/Tank.java
@@ -1,22 +1,25 @@
 package com.demo.tank.course3;
 
 import java.awt.*;
+import java.util.Random;
 
 public class Tank {
     private int x,y;
     private Direction dir;
-    private static final int SPEED = 10;
-    private boolean moving;
+    private static final int SPEED = 8;
+    private boolean moving = false;
     private boolean living = true;
+    private Group group = Group.BAD;
     private TankFrameV3 tankFrame;
     public static final int WIDTH = ResourceManager.tankD.getWidth();
     public static final int HEIGHT = ResourceManager.tankD.getHeight();
+    private Random random = new Random();
 
-
-    public Tank(int x, int y, Direction dir, TankFrameV3 tankFrame) {
+    public Tank(int x, int y, Direction dir, Group group, TankFrameV3 tankFrame) {
         this.x = x;
         this.y = y;
         this.dir = dir;
+        this.group = group;
         this.tankFrame = tankFrame;
     }
 
@@ -55,6 +58,13 @@ public class Tank {
             default:
                 break;
         }
+//        if(random.nextInt(10) > 8) this.fire();
+    }
+
+    public void fire() {
+        int bx = x + Tank.WIDTH/2 - Bullet.WIDTH/2;
+        int by = y + Tank.HEIGHT/2 - Bullet.HEIGHT/2;
+        tankFrame.bullets.add(new Bullet(bx, by, this.dir, this.group, tankFrame));
     }
 
     public void die(){
@@ -101,9 +111,11 @@ public class Tank {
         this.living = living;
     }
 
-    public void fire() {
-        int bx = x + Tank.WIDTH/2 - Bullet.WIDTH/2;
-        int by = y + Tank.HEIGHT/2 - Bullet.HEIGHT/2;
-        tankFrame.bullets.add(new Bullet(bx, by, this.dir, tankFrame));
+    public Group getGroup() {
+        return group;
+    }
+
+    public void setGroup(Group group) {
+        this.group = group;
     }
 }
diff --git a/src/com/demo/tank/course3/TankFrameV3.java b/src/com/demo/tank/course3/TankFrameV3.java
index a994fea..5c136cf 100644
--- a/src/com/demo/tank/course3/TankFrameV3.java
+++ b/src/com/demo/tank/course3/TankFrameV3.java
@@ -13,10 +13,11 @@ public class TankFrameV3 extends Frame {
     public static final int GAME_HEIGHT = 600;
     Image image = null;
 
-    Tank tank = new Tank(500, 500, Direction.UP, this);
+    Tank tank = new Tank(500, 500, Direction.UP, Group.GOOD,this);
 //    Bullet bullet = new Bullet(520, 440, Direction.UP);
     List<Bullet> bullets = new ArrayList();
     List<Tank> enemyTanks = new ArrayList<>();
+    Explode explode = new Explode(200, 300, this);
 
     public TankFrameV3(){
         setVisible(true);
@@ -57,6 +58,8 @@ public class TankFrameV3 extends Frame {
 
         tank.paint(g);
 
+        explode.paint(g);
+
         for(int i = 0; i< enemyTanks.size(); i++){
             enemyTanks.get(i).paint(g);
         }