单选题下列程序段的执行结果为 Dim A(3，3) For M=1 To 3 For N=1 To 3 If N=M Or N=3-M+1 Then A(M,N) =1 Else A(M,N) =0 End If Next N Next M For M=1 To 3 For N=1 To 3 Print A(M,N) Next N Print Next M Ａ) 1 0 0 　0 1 0 0 0 0 Ｂ) 1 1 1 1 1 1 1 1 1 Ｃ) 0 0 0 0 0 0 0 0 0 Ｄ) 1 0 1 0 1 0 1 0 1

【正确答案】 D

【答案解析】[解析] 题中以嵌套For循环为数组A(3，3)赋值，此过程中，如果A(M，N)符合条件"N=M OR N=3-M+1"则此项赋1，否则赋0。以A(1,1)为例，由于M=N=1，故A(1,1)=1。依次类推： A(1,1) =1 A(2,1) =0 A(3,1) =1 A(1,2) =0 A(2,2) =1 A(3,2) =0 A(1,3) =1 A(2,3) =0 A(3,3) =1