1. (2020·浙江模拟) 有如下VB程序段：

s = “7218634594”：n = Len(s)

t = 0

For i = 1 To n - 1

 a(i) = Val(Mid(s, i, 2))

Next i

For i = 1 To n - 2 Step 2

k = i

For j = i + 2 To n - 1 Step 2

  If a(j) < a(k) Then k = j

Next j

If k <> i Then

  temp=a(i)：a(i)=a(k)：a(k)=temp

    t = t + 1

End If

Next i

Text1.Text = Str(t)

该程序段运行后，文本框Text1中显示的内容是(  )