若要使动画播放完该场景时停止音乐的播放,需要执行的操作是( )

a=2
b=a+5
If a Mod b=2 Then
a=a+2
b=a+b
End If
b=b+2
Text1.Text=Str(b)
该程序运行后,文本框Text1上显示的内容为。
Private Sub Command1_Click()
Dim i As Integer, S As String
Dim str As String, ch As String
str = Text1.Text
List1.Clear
For i = 1 To Len(str)
ch = ①
S = convert(ch)
List1.AddItem ch & "==>" & S
Next i
End Sub
Private Function convert(ch As String) As String
Dim m As Integer, k As Integer, n As Integer, i As Integer
convert = ""
n = Asc(ch)
Do While n > 0
②
convert = m & convert
If m = 1 Then
k = k + 1
End If
n = n \ 2
Loop
For i = 1 To 7 - Len(convert) '将字符的二进制代码补足7位
convert = "0" & convert
Next i
If k Mod 2 = 0 Then
convert = ③
Else
convert = "0" & convert
End If
End Function
程序中划线处①的代码应为。
程序中划线处②的代码应为。
程序中划线处③的代码应为。

1图
2图
3图
此时程序正在执行的语句是( )
Private Sub Command1_ Click( )
Dim a As Integer
Dim s As String
s ="year:
a = 2016
s=s+a
Text1.Text = Str(a)
End Sub
①以字节为单位进行加密处理;
②将1个字节的8位二进制数右移以为,最高位用右移出的最低位填充;
③将处理好的8位二进制分割成前4位与后4位两个二进制数;
④分别将上述两个4位二进制转换为十六进制数;
所得两个十六进制数按先后顺序连接,即为该字节的密文。根据以上要求回答以下问题: