C#中的线程概念

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Threading;

namespace ConsoleApplication17
{
  class Program
  {
    static void Main(string[] args)
    {
        System.Threading.ThreadStart th1 = new System.Threading.ThreadStart(prnt);
        Thread th = new Thread(th1);
        th.Start();
        bool t = th.IsAlive;
        for (int i = 0; i < 10; i++)
        {
            Console.WriteLine(i + "A");
        }
    }

    private static void prnt()
    {
        for (int i = 0; i < 10; i ++)
        {
            Console.WriteLine(i + "B");
        }
    }
  }
}

我期待输出如下： –

1A
2A
1B
3A
2B...

因为我相信主线程和新创建的线程都应该同时执行.

但是输出是有序的,首先调用prnt函数,然后执行Main方法for循环.