Dim i As Integer, j As Integer, k As string, n As Integer

n = 3

List1.Clear

For i=1 To n

k =″″

For j=1 To i

k = k+″*″

Next j

List1.AddItem k

Next i

该程序运行后, 在列表框List中显示的是（   ）

Private Sub Command1_Click()

    Dim x As Integer

    x=Val(Text1．Text)

    Label1．Caption=Str(x) & prime(x，2)

End Sud   

Function prime(n A Integer m A Integer)As String

    If n=m Then

        prime=“是素数。”

    ElseIf n<2 Or n Mod m=0 Then

        prime=“不是素数。”

    Else

    prime=prime(n，m+1)

End If

End Function

在文本框Text1中输入的值是123，并执行程序后，自定义函数prime( )被执行的次数是（  ）

以原文：Hello，密钥：123为例，“H”转换为ASCII码后加上密钥的第一个数字1，再转换回ASCII字符，得到“I”;“e”转换为ASCII码，加上密钥的第二个数字2，转换回ASCII得到“g”;“l”则加上密钥的第三个数字3得到“o”;随后原文又出现“1”，但是密钥中的数字已经用完了，则密钥从头开始，加上“1”，得到“m”;“o”则得到“q”，最后产生密文“Igomq”。

具体程序如下，但是有两处加框的代码错误，请改正：

Dim code As String, key As String

Dim i As Integer, res_code As String

Dim l_code As Integer, l_key as Integer

Private Sub Command1_Click( )’加密程序

code = Text1.Text

key = Text2.Text

l_code =Len(code)

l_key =Len(key)

res_code = “”

For i = 1 To      ‘⑴

 c =Asc(Mid(code, i, 1))

 k =      ‘⑵

 res_code = res_code +Chr(k + c)

Next i

Text3.Text = res_code

End Sub

Private Sub Command2_Click( )

‘解密程序略

End Sub

⑴{#blank#}1{#/blank#} ⑵{#blank#}2{#/blank#} 

Private Sub Command2_Click()

Dim i As Integer, j As Integer, tmp As Integer

Dim s1 As String, t As Integer, s2 As String

t=1

For i=1 To n-2

    For j= To n Step 2     ‘改错

        If a(i)*t>a(j)*t Then

            tmp =a(i): a(i)= a(j): a(j)=tmp

        End if

    Next j

                   ‘填空①

Next i

For i =1 To n

    If     Then       ‘填空②

        s1 =s1 Str(a(i))

    Else

        s2=s2+Str(a(i))

    End If

Text2. Text=“奇数位：”+s1

Text3. Text=“偶数位：”+s2

End Sub

回答以下问题：

Dim a(1 To 100) As Integer

Dim b(1 To 100) As Integer

Dim c As Integer

a(1) = 0: a(2) = 2: b(1) = 1: b(2) = 2: c = 0

For i = 2 To 6

  a(i + 1) = 2 * a(i) - a(i - 1)

  b(i + 1) = b(i) ^ 2 / b(i - 1)

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

Next i

Label1.Caption = Str(c)

该程序运行后，Label1中显示的内容是（  ）