a(1)=1：a(2)=1

  b(1)=1：b(2)=2

  For i=3 To 5

a(i)=a(i-1)+a(i-2)

b(i)=b(i-1)+a(i)

Next i

执行该程序段后，数组元素b(5)的值为（  ）

Private Sub Command1_Click()

Dim a As Integer, b As Integer

a = 5: b = 3

Print work(a, b)

End Sub

Function work(x As Integer, y As Integer) As Integer

If (x < y) Then

work = 0

Exit Function

End If

If (y = 0) Then

work = 1

Exit Function

End If

work = work(x - 1, y - 1) + work(x - 1, y)

End Function

Function s(n As Integer) As Integer

 If n=1 Then

   s=1

 Else

   s=s(n-1)+n

 End If

End Function

Private Sub Form_Click()

 Dim x As Integer

 x=s(4)

 Print x

End Sub

程序运行时,单击窗体后,变量x的值为（  ）

Function f(i As Integer)

    If i=1 Then

      f=2

    Else

      f=2 * 10 ^ (i-1)+f(i-1)

    End If

End Function

Private Sub Command1_Click()

    Dim n As Integer, s As Integer, i As Integer

    n=Val(Text1.Text)

    s=0

    For i=1 To n

      s=s+f(i)

    Next i

    Label1.Caption=Str(s)

End Sub

若在Text1中输入5，则Label1显示的内容为（  ）

def f(a , n):

    n=n-1

    if n=0:

        return a

    else:

        return f（a-1, n）+f（a+1, n）

print（f（5, 3））

程序运行后，输出的结果是（   ）