Private Sub Command1_click()

Dim s as integer,I as integer

S=0

For i=1 to 20 step 3

      s=s+(-1)^i*i

Next i

Label1.caption=str(i)

Label2.caption=str(s)

End Sub

S=0

For i=1 To 3

  s=s+2

Next i

Print s

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（  ）

s = 0

a = 5

For i = 1 To 10 Step 2

    a = a + i

    s = a * i

Next i

问：该程序段运行后，

Private Sub Command1_Click()

Dim sum As Double, x As Double

 sum = 0

 n = 0

 For i = 1 To 5

  x = n / i

  n = n + 1

  sum = sum + x

 Next

End Sub

该程序通过For循环计算sum的值，下列表达式的值与sum相等的是（  ）