为什么报错，结果能弄出来

int [] score = new int[]{90,65,88,70,46,81,100,68};    

        string [] name = new string []{"景珍", "林惠洋", "成蓉", "洪南昌", "龙玉民", "单江开", "田武山", "王三明"};

        int sum = 0;

        int avg = 0;

        foreach(int x in score)

        {

            sum += x;

        }

        avg = sum/score.Length;

        Console.Write("平均分是" + avg + "，高于平均分的有：");

        Console.WriteLine();

        for(int i=0; i<=score.Length;i++)

        {

            if(score[i]>=avg)

                Console.Write(name[i]+" ");

        }