一维数组怎么给二维数组赋值

一维数组如何给二维数组赋值？
一维数组string[] a1 = new string[91];
二维数组string[13,7] a2 = new string[13,7];
请问如何用a1把a2填充满

[解决办法]

C# code

            string[] a1 = new string[91];            string[,] a2 = new string[13,7];            int k = 0;            for (int i = 0; i < 13; i++)            {                for (int j = 0; j < 7; j++)                {                   a2[i, j] = a1[k];                   k++;                }            }