Dim s As Double, x As Double, n As Integer, i As Integer

s=0:n=0

For i= 1 to 4

  n=n+1

  x=(n-1)/(n+1)

  s=s+x

Next i

该程序段计算的数学表达式是（   ）

i = 1

 Do While i <= 6

    t = Int(Rnd * 10) + 1

    If t Mod 2 = i Mod 2 Then a(i) = t : i = i + 1

Loop

For i = 1 To 2

   k = 1

   For j = 1 To 6 - i * 2

     If a(j) * k > a(j + 2) * k Then

       t = a(j) :  a(j) = a(j + 2) :  a(j + 2) = t

     End If

     k = -k

   Next j

Next i

执行该程序段后，数组元素a(1)到a(6)的值可能是（  ）

a = 5

b = Len("1011")

If a > b Then

  Label1.Caption = "请重新输入"

Else

 Label1.Caption = "欢迎光临"

End If

该程序段运行后，在标签Label1上显示的是{#blank#}1{#/blank#}。