C#线程问题 急死我啦 帮帮忙- -!

这个是我做的摇奖机的一个东东，我这样写的线程没有问题。但是我发现点击了停止按钮(STOP启动按钮事件那里)，这些显示的9个数字都是一模一样的，我再点击开始(Start启动按钮事件那里)。他就报错，大家帮帮忙 ,偶郁闷啦
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Threading;namespace 摇奖机
{
    public partial class ERNIE : Form
    {
        private Point mouseOffset;//定义一个变量，用于存放鼠标的坐标
        private bool isMouseDown = false;//定一个布尔变量，用于判断鼠标状态
        //Thread[] th = new Thread[9];
        ThreadStart t;
        Thread th1;
        Thread th2;
        Thread th3;
        Thread th4;
        Thread th5;
        Thread th6;
        Thread th7;
        Thread th8;
        Thread th9;
        public ERNIE()
        {
            InitializeComponent();
            th1 = new Thread(new ThreadStart(rnd1));
            th2 = new Thread(new ThreadStart(rnd2));
            th3 = new Thread(new ThreadStart(rnd3));
            th4 = new Thread(new ThreadStart(rnd4));
            th5 = new Thread(new ThreadStart(rnd5));
            th6 = new Thread(new ThreadStart(rnd6));
            th7 = new Thread(new ThreadStart(rnd7));
            th8 = new Thread(new ThreadStart(rnd8));
            th9 = new Thread(new ThreadStart(rnd9));
            //for (int i = 0; i < 9; i++)
            //{
                //th[i] = new Thread(t);
           // }
        }
//===============================================Start启动按钮事件=======================================
        public void BTstart_Click(object sender, EventArgs e)
        {
            ERNIE.CheckForIllegalCrossThreadCalls = false;
            th1.Start();
            th2.Start();
            th3.Start();
            th4.Start();
            th5.Start();
            th6.Start();
            th7.Start();
            th8.Start();
            th9.Start();
        }
//===============================================STOP启动按钮事件=======================================
        private void button1_Click(object sender, EventArgs e)
        {
            th1.Abort();
            th2.Abort();
            th3.Abort();
            th4.Abort();
            th5.Abort();
            th6.Abort();
            th7.Abort();
            th8.Abort();
            th9.Abort();
            LB10.Text = LB1.Text;
            LB11.Text = LB2.Text;
            LB12.Text = LB3.Text;
            LB13.Text = LB4.Text;
            LB14.Text = LB5.Text;
            LB15.Text = LB6.Text;
            LB16.Text = LB7.Text;
            LB17.Text = LB8.Text;
            LB18.Text = LB9.Text;
        }
//===============================================线程控制随机数==========================================
        public void rnd1()
        {
            Random r = new Random();
            int x = r.Next(0,10);
            LB1.Text=x.ToString();
            Thread.Sleep(10);
            rnd1();
        }
        public void rnd2()
        {
            Random r = new Random();
            int x = r.Next(0,10);
            LB2.Text = x.ToString();
            Thread.Sleep(10);
            rnd2();
        }
        public void rnd3()
        {
            Random r = new Random();
            int x = r.Next(0,10);
            LB3.Text = x.ToString();
            Thread.Sleep(10);
            rnd3();
        }
        public void rnd4()
        {
            Random r = new Random();
            int x = r.Next(0,10);
            LB4.Text = x.ToString();
            Thread.Sleep(10);
            rnd4();
        }
        public void rnd5()
        {
            Random r = new Random();
            int x = r.Next(0,10);
            LB5.Text = x.ToString();
            Thread.Sleep(10);
            rnd5();
        }
        public void rnd6()
        {
            Random r = new Random();
            int x = r.Next(0,10);
            LB6.Text = x.ToString();
            Thread.Sleep(10);
            rnd6();
        }
        public void rnd7()
        {
            Random r = new Random();
            int x = r.Next(0,10);
            LB7.Text = x.ToString();
            Thread.Sleep(10);
            rnd7();
        }
        public void rnd8()
        {
            Random r = new Random();
            int x = r.Next(0,10);
            LB8.Text = x.ToString();
            Thread.Sleep(10);
            rnd8();
        }
        public void rnd9()
        {
            Random r = new Random();
            int x = r.Next(0,10);
            LB9.Text = x.ToString();
            Thread.Sleep(10);
            rnd9();
        }//============================================鼠标移动状态事件===========================================
        private void ERNIE_MouseDown(object sender, MouseEventArgs e)//鼠标按下事件
        {
            if (e.Button == MouseButtons.Left)//如果鼠标点击的为左键
            {
                mouseOffset = new Point(-e.X, -e.Y);//得到鼠标当前位置坐标赋值于mouseoffset
                isMouseDown = true;//鼠标状态为真
            }
        }        private void ERNIE_MouseMove(object sender, MouseEventArgs e)//鼠标移动事件
        {
            if (isMouseDown)//如果鼠标的状态为真
            {
                Point mousePos = Control.MousePosition;//鼠标移动变量赋值于mousePos
                mousePos.Offset(mouseOffset.X, mouseOffset.Y);//鼠标当前位置变量赋值于mousePos
                this.Location = mousePos;//窗口跟着做相应的移动
            }
        }        private void ERNIE_MouseUp(object sender, MouseEventArgs e)//鼠标松开时间
        {
            if (e.Button == MouseButtons.Left)//如果鼠标松开的为左键
            {
                isMouseDown = false;//则鼠标状态为假
            }
        }
    }
}