diff --git a/docs/坦克大战笔记.docx b/docs/坦克大战笔记.docx
index b3f2d42..0e717e5 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/course4/Bullet.java b/src/com/demo/tank/course4/Bullet.java
index 4beea81..392ced0 100644
--- a/src/com/demo/tank/course4/Bullet.java
+++ b/src/com/demo/tank/course4/Bullet.java
@@ -5,7 +5,7 @@ import java.awt.*;
 public class Bullet {
     private int x, y;
     private Direction direction;
-    private static final int SPEED = 5;
+    private static final int SPEED = 10;
     public static final int WIDTH = ResourceManager.bulletD.getWidth();
     public static final int HEIGHT = ResourceManager.bulletD.getHeight();
     private boolean live = true;
@@ -68,6 +68,10 @@ public class Bullet {
         if(bulletRect.intersects(tankRect)){
             tank.die();
             this.die();
+            //爆炸
+            int ex = tank.getX() + Tank.WIDTH/2 - Explode.WIDTH/2;
+            int ey = tank.getY() + Tank.HEIGHT/2 - Explode.HEIGHT/2;
+            tf.explodes.add(new Explode(ex, ey , tf));
         }
     }
 
diff --git a/src/com/demo/tank/course4/Explode.java b/src/com/demo/tank/course4/Explode.java
index 7fbf453..39d57b1 100644
--- a/src/com/demo/tank/course4/Explode.java
+++ b/src/com/demo/tank/course4/Explode.java
@@ -8,7 +8,6 @@ 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 TankFrameV4 tf;
 
     private int step = 0;
@@ -23,7 +22,8 @@ public class Explode {
     public void paint(Graphics g){
         g.drawImage(ResourceManager.explodes[step++], x, y, null);
         if(step >= ResourceManager.explodes.length){
-            step = 0;
+            //播放完爆炸效果图片， remove
+            tf.explodes.remove(this);
         }
     }
 
diff --git a/src/com/demo/tank/course4/Tank.java b/src/com/demo/tank/course4/Tank.java
index 4fcf7dc..3029409 100644
--- a/src/com/demo/tank/course4/Tank.java
+++ b/src/com/demo/tank/course4/Tank.java
@@ -7,7 +7,7 @@ public class Tank {
     private int x,y;
     private Direction dir;
     private static final int SPEED = 8;
-    private boolean moving = false;
+    private boolean moving = true;
     private boolean living = true;
     private Group group = Group.BAD;
     private TankFrameV4 tankFrame;
@@ -58,7 +58,18 @@ public class Tank {
             default:
                 break;
         }
-//        if(random.nextInt(10) > 8) this.fire();
+        if(this.group == Group.BAD) {
+            if(random.nextInt(10) == 5){
+                this.fire();
+            }
+            if(random.nextInt(100) > 95){
+                this.randomDirection();
+            }
+        }
+    }
+
+    private void randomDirection() {
+          this.dir = Direction.values()[random.nextInt(4)];
     }
 
     public void fire() {
diff --git a/src/com/demo/tank/course4/TankFrameV4.java b/src/com/demo/tank/course4/TankFrameV4.java
index dc4e6be..e6f2109 100644
--- a/src/com/demo/tank/course4/TankFrameV4.java
+++ b/src/com/demo/tank/course4/TankFrameV4.java
@@ -9,19 +9,20 @@ import java.util.ArrayList;
 import java.util.List;
 
 public class TankFrameV4 extends Frame {
-    public static final int GAME_WIDTH = 800;
-    public static final int GAME_HEIGHT = 600;
+    public static final int GAME_WIDTH = 1080;
+    public static final int GAME_HEIGHT = 800;
     Image image = null;
 
-    Tank tank = new Tank(500, 500, Direction.UP, Group.GOOD,this);
+    Tank tank = new Tank(380, 660, 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);
+
+    List<Explode> explodes = new ArrayList<>();
 
     public TankFrameV4(){
         setVisible(true);
-        setBounds(500, 200 , GAME_WIDTH, GAME_HEIGHT);
+        setBounds(400, 100 , GAME_WIDTH, GAME_HEIGHT);
         setResizable(false);
         setTitle("tank war");
         this.addKeyListener(new MyKeyListener());
@@ -54,12 +55,11 @@ public class TankFrameV4 extends Frame {
         g.setColor(Color.WHITE);
         g.drawString("当前子弹数量:" + bullets.size(), 60, 50);
         g.drawString("当前敌人数量:" + enemyTanks.size(), 60, 80);
+        g.drawString("当前爆炸数量:" + explodes.size(), 60, 100);
         g.setColor(color);
 
         tank.paint(g);
 
-        explode.paint(g);
-
         for(int i = 0; i< enemyTanks.size(); i++){
             enemyTanks.get(i).paint(g);
         }
@@ -68,11 +68,16 @@ public class TankFrameV4 extends Frame {
             bullets.get(i).paint(g);
         }
 
+        //碰撞检测
         for(int i = 0; i< bullets.size(); i++){
             for(int j=0; j< enemyTanks.size(); j++){
                 bullets.get(i).collideWith(enemyTanks.get(j));
             }
         }
+
+        for (int i = 0; i< explodes.size(); i++){
+            explodes.get(i).paint(g);
+        }
 //        for(Iterator<Bullet> it = bullets.iterator(); it.hasNext();){
 //            Bullet b = it.next();
 //            if(!b.isLive()){
@@ -127,7 +132,7 @@ public class TankFrameV4 extends Frame {
                 case KeyEvent.VK_S:
                     bD = false;
                     break;
-                case KeyEvent.VK_J:
+                case KeyEvent.VK_SPACE:
                     tank.fire();
                     break;
                 default: