图a

图b为标准ASCII码表供你参考（其中ASCII为1-32,127的字符为特殊符号，不能用作密码）：

图b

实现上述功能的VB程序代码如下，请回答以下问题：

Const n = 8

Dim a(1 To n) As Integer

For i = 1 To n

    a(i) = Int(Rnd * 20)

Next i

x = n \ 2

For i = x To 2 Step -1

    For j = 1 To i - 1

      If a(j) < a(i) Then

        t = a(j): a(j) = a(i): a(i) = t

      End If

    Next j

Next i

i = n

Do While i > x + 1

    k = i

    For j = i - 1 To x + 1 Step -1

      If a(j) > a(k) Then k = j

    Next j

    If k <> i Then

      t = a(k): a(k) = a(i): a(i) = t

    End If

    i = i - 1

Loop

执行完这段代码后，数组 a 中各个元素的值可能的是（  ）

Dim a(1 to 20) As Integer

For i=2 to 10

For j=2 to 20\i

a(i*j)=a(i*j) +1

Next j

Next i

该程序段运行后，数组a中元素值为0的个数是（  ）