int max = 0;
string[,] stu = new string [8,2] { { "吳松", "89" },...};
for (int j = 0; j < 8; j++)
{
if (Convert.ToInt32(stu[0, 1])< Convert.ToInt32( stu[j, 1])) max = j; }
Console.WriteLine("分數最高的是{0},分數是{1}", stu[max, 0], stu[max, 1]);