空白矩形框中应该填入的是（   ）

Private Sub Command1_Click()

Dim x As String, i As Integer

For i = 1 To 10

  If i Mod x = 1 Then

     x = "奇数"

  Else

    x = "偶数"

Next i

……

End Sub

产生此错误的语句是(   )。

  If (a Mod 3 = 0) Or (b Mod 3 = 0) Then

 c = a * b

  Else

  c = a + b

  End If

执行后变量c的值为（   ）

n = 6

d(1) = 23: d(2) = 31: d(3) = 19: d(4) = 33: d(5) =58: d(6) = 28

k = Abs(d(2) - d(1))

For i = 3 To n

 If Abs(d(i) - d(i - 1)) > k Then k = Abs(d(i) - d(i - 1))

Next i

Text1.Text = Str(k)

上述程序段执行后，文本框Text1显示的内容是（  ）

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（  ）